Wyoming

Wyoming is a state of extremes. Around Lander and in the Bighorn Mountains, bone-white Madison limestone and Bighorn dolomite give up pocketed, steep sport climbing that draws destination traffic every summer. In the southeast corner, Sherman Granite erupts into the wind-scoured domes of Vedauwoo, a wide-crack and offwidth proving ground unlike almost anywhere else in the country. Devils Tower rises alone out of the Black Hills grassland, an Eocene phonolite intrusion fluted into parallel cracks that has drawn crack climbers since 1937 — how it was emplaced has been argued for over a century, so we no longer call it a laccolith outright. To the west, the Wind River Range and the Tetons carry some of the best alpine granite in the Lower 48. Casper and Cody add canyon and gorge climbing on granite and limestone respectively, and Cody’s South Fork of the Shoshone is one of the most storied ice climbing testing grounds in North America. Public land is the rule almost everywhere, but enclaves of private land are scattered through it, especially around the Sweetwater Rocks, and access depends on respecting the boundary between the two.

The season is short at altitude and long at the canyons: Fremont Canyon and Guernsey’s south-facing limestone climb through much of the winter, while the Wind Rivers and the Snowy Range hold snow into July. Raptor nesting closures, grazing-season road closures, and one long-standing voluntary June closure at Devils Tower all shape when a given wall is fair game.

Plate reserved — hand-drawn map & photographs to come

The rock of Wyoming

New Mexico’s geologic story is chemistry — what erupted, what precipitated. Wyoming’s is architecture. A piece of some of the oldest continental crust on Earth was buried under a mile and a half of shallow-sea limestone and desert sandstone, then shoved bodily upward in discrete blocks with the sedimentary cover peeling off their flanks, then buried again in its own debris, then dug back out. Almost every Wyoming crag is explained by where it sits in that sequence: on the exhumed Archean core of an uplift, on the tilted Paleozoic carbonate wrapped around that core, or on something young punched through the pile afterwards.

The basement is the Wyoming Province, 3.5 to 2.5 billion years old, exposed wherever a Laramide uplift has stripped its cover — the Beartooths, the Bighorns, the Wind Rivers, the Tetons, the Laramie Range, the Granite Mountains. In the southeast corner the state stops being Archean: the Cheyenne belt is the suture where the Paleoproterozoic Yavapai province — the same one that floors New Mexico — was welded on at 1.78–1.74 Ga. Across that seam, at about 1.43 Ga, the Sherman batholith and the Laramie anorthosite complex intruded, part of the same continent-wide 1.4 Ga pulse that gave New Mexico the Sandia pluton. That granite is Vedauwoo.

Above the basement is a gap of roughly two billion years. In the Bighorns the Middle Cambrian Flathead Sandstone lies directly on deeply weathered 2.95 Ga granite, fossil grus and paleosol preserved at the contact — one of the best places on Earth to put a hand on both sides of the Great Unconformity. Then the platform: Flathead, Gros Ventre, Gallatin, the thin but real Bighorn Dolomite, Darby, the Madison Limestone, the red Amsden, and the eolian Tensleep Sandstone at the rim. Two facts from that list run through the whole chapter. The Madison is the reason Wyoming has sport climbing — it is thick, massive, mechanically strong and it takes solution features. And the Bighorn Dolomite is genuinely thin, 82 to 138 feet in the Bighorn Mountains, which is a problem for the universal climbers’ habit of calling every carbonate crag in the state Bighorn Dolomite.

The Laramide orogeny, 75 to 55 Ma, is what made all of it climbable — thick-skinned deformation driving basement blocks 3 to 20 km up along faults dipping 25° to 40°, tilting the carbonate section off their flanks into cliffs. The uplifts are the map of Wyoming climbing: the Bighorns give Ten Sleep and the eastern canyons, the Wind Rivers give the alpine granite and the Lander limestone, the Laramie Range gives Vedauwoo, the Granite Mountains give Fremont Canyon and the Sweetwater Rocks. Afterwards came Eocene magma in two very different forms — the Absaroka volcanic field (53–43 Ma, 29,000 km³ of mostly altered andesite) in the northwest, and a swarm of alkaline intrusions into the flank of the Black Hills at ~49 Ma, one of which is Devils Tower. The Tetons then got raised a second time by a normal fault that started moving 13 to 7 Ma and has not stopped. And ice did the sculpting: the Pinedale glaciation is named for the moraines on the west side of the Wind Rivers.

The recurring rock types

Rock	Where	Jointing	Holds	Watch out for
Madison Limestone, ~350 Ma	Ten Sleep, Sinks Canyon, Story, Tongue River, Crazy Woman, Shoshone Canyon, Rodeo Wall, Guernsey	massive, joint-controlled walls; bedding roofs where thinner-bedded	pockets from dissolution and paleokarst, incut edges, plates	solution-breccia bands — collapsed, re-cemented rubble hiding inside a good formation; seepage for days
Bighorn Dolomite, Ordovician	Wild Iris, Baldwin Creek, road level at Ten Sleep	massive but thin — 82–138 ft in the Bighorns	monos and two-finger pockets in horizons, sharp fresh rims	pocket rims break; a sugary, vuggy band holds bolts badly
Archean granitoid, 2.5–2.95 Ga	Cirque of the Towers, Deep Lake, upper Sinks, Fremont Canyon, Lankin Dome, Dome Rock, Shoshone Canyon	a few well-organised joint sets, plucked by ice into towers; sheeting joints on domes	inch-sized crystals, crimps, clean splitters	coarse crystals that hurt in jams; grus; frost-shattered summit ridges and ledges
Archean layered gneiss	the Tetons, northern Wind Rivers (Titcomb, Gannett)	foliation-parallel flakes and sheets; cracks follow contacts and blank out	incut edges where layering weathers	four or five different rocks on one face — quality changes within a pitch
Sherman Granite, 1.43 Ga	Vedauwoo	widely spaced ENE joints through massive blocks	almost nothing between the cracks	flared jams from subsurface corestone rounding; 54% feldspar with scalpel edges; grus underfoot
Phonolite porphyry, ~49 Ma	Devils Tower	columnar cooling joints, 5-sided, 6–8 ft across	the joints are the routes — fingers to offwidth to chimney	the top ~100 ft is cross-fractured into small blocks; exterior columns fall as the soft sediment beneath them erodes; polish
Medicine Peak Quartzite, 2.4–2.0 Ga	Snowy Range	shallow, flaring, blind joints	edges and bedding breaks; no pockets	superb friction dry, poor wet — water sits on it rather than in it; sparse gear
Tensleep Sandstone, Pennsylvanian	lower Sinks Canyon	joint-bounded cracks, cross-bed-parallel flakes	crack systems; a friable weathering surface	eolian sand in a little cement — give it a day or more after rain
Absaroka volcaniclastic breccia, 53–43 Ma	the South Fork ice	flat-lying alternating resistant and soft bands	none worth trusting	“kitty litter” — rock protection is poor to useless; rockfall in every thaw

Two Wyoming-specific things to carry. The Great Unconformity is climbable here — at Shoshone Canyon and in Sinks and Fremont Canyons you can boulder within a few metres of a two-billion-year gap. And freeze–thaw above 7,000 ft is the dominant active process on almost every wall in the state, which means alpine rockfall is overwhelmingly a ledge-and-gully problem rather than a face problem: the clean lower walls were plucked by ice, and the debris sits on the ledges above them.

Lander area

Wyoming’s sport-climbing capital and home to the International Climbers’ Festival every July, spread across a band of Paleozoic carbonate in and above Sinks Canyon State Park, with Wild Iris — higher, cooler, more remote — as the marquee crag.

Lander sits at the southeastern nose of the Wind River Range, and the Laramide uplift of that range tilted the whole Paleozoic section off its flank. So a drive up Sinks Canyon is a drive down the section and back in time: Tensleep Sandstone at the mouth, then Madison Limestone and Bighorn Dolomite through the middle, then Archean granite at the top. Every crag here is a bench on that tilted stack, or the basement beneath it — which is why one small town offers sandstone cracks, pocketed carbonate and granite slabs within twenty minutes of each other. The Sinks themselves are the carbonate’s own plumbing: the Popo Agie vanishes into a cavern in the Madison and takes over two hours to travel the quarter-mile to the Rise, by dye test. And the Wild Iris monos, whatever the local story says, are not gas bubbles — they are dolomitisation porosity, selective dissolution and karst, which is why pockets come in horizons and clusters rather than at random. Read the band, not the wall.

Area	Near	Rock	Style	Size	Grades	Notes
Wild Iris	Lander (~24 mi SW)	Bighorn Dolomite, Ordovician — bone-white, massive, siliceous	Sport, pockets	Several hundred routes	5.4–5.14d	High (~9,000 ft), aspen-and-wildflower setting; Shoshone National Forest.
Sinks Canyon	Lander (~10 min)	A tilted section in one drainage: Tensleep Sandstone low, Madison and Bighorn carbonate through the middle, Archean granite at the top	Predominantly sport, some trad	~800 routes	5.7–5.14	Named for the Popo Agie River’s disappearance and reappearance; Sinks Canyon State Park plus Shoshone NF.
Fossil Hill	Lander area, above Sinks	Carbonate of the Lander belt — Bighorn and/or Madison; no source names a formation at the crag	Sport	~60–80 routes across three sub-sectors, plus The Hideout	Mostly 5.9–5.12	Voluntary seasonal raptor/wildlife closure has applied roughly June 9–Aug 15 in past years — confirm current dates locally.
Baldwin Creek	Lander (~15 mi)	Dolomite — locally called the best rock in Lander	Sport	~50 routes	5.11–5.14	Promoted from “unverified” by the geology pass: a south-facing dolomite cliff on BLM land, which has its own Baldwin Creek Climbing Area page. 4WD approach plus a hike on top. The road closes in winter for elk habitat management.

Ten Sleep Canyon

Everyone calls this Bighorn Dolomite, and the canyon walls say otherwise. Forest Service interpretive signage gives the benches as Tensleep Sandstone at the rim, the red Amsden recess, the Darwin Sandstone ledge, then gray cliffs of Madison Limestone — with the Bighorn Dolomite below that, at road level near Leigh Creek, whose upper member is named for the creek. Both units are genuinely here. But the Bighorn is 25 to 42 metres thick and the Madison is 490 to 700 feet, and a 250-foot crag cannot sit inside a 130-foot formation. What saves the climbers’ usage is that the Wyoming Madison is itself heavily dolomitised — so the lithology is right even where the formation name is wrong. See Part II for the full account, including how to read the canyon’s gold, white and blue walls as a rock-quality map.

Area	Near	Rock	Style	Size	Grades	Notes
Ten Sleep Canyon	Ten Sleep / Worland	Madison Limestone above, Bighorn Dolomite at road level — climbers call all of it dolomite, and the Wyoming Madison is itself heavily dolomitised	Sport, some trad	~1,000–1,500+ routes	5.6–5.14, concentrated 5.10–5.12	One of the premier sport destinations in the interior West; most routes within a 15-minute walk of the road. Bighorn National Forest.

Devils Tower

Not basalt, and the distinction is not pedantry: phonolite porphyry, about 49 Ma, one of a swarm of alkaline intrusions punched into the flank of the rising Black Hills. Phonolite is silica-undersaturated — it carries nepheline where a granite would carry quartz — and it takes its name from the ringing sound its plates make when struck, which any climber who has tapped a suspect flake up there has heard. The magma cooled slowly enough to produce the world’s finest columnar jointing: mostly five-sided columns, six to eight feet across at the base tapering to four at the top, some running 590 feet unbroken. The routes are the joints — a columnar body has no faces, only column flanks and the partings between them, which is why the Tower is a crack climb from fingers through offwidth to chimney and why the cracks are so uniformly parallel-sided that cams work and nuts often don’t. The USGS also explains the standard warning about the last hundred feet: the joints are smooth in the middle of the Tower but wavy near the top, where cross-fractures divide the columns into small irregular blocks. And the boulder field is not an ancient landform — as the soft sediments at the base erode, exterior columns lose their lateral support and fall.

Area	Near	Rock	Style	Size	Grades	Notes
Devils Tower (Bear Lodge / Mato Tipila)	Sundance / Hulett	Phonolite porphyry, ~49 Ma — columnar, mostly five-sided, 6–8 ft across	Trad crack, a handful of bolted lines	200+ routes	5.7–5.13a	The Durrance Route (5.7, 1938) carries ~85% of summit traffic. A voluntary June climbing closure, requested by the NPS with area tribes out of respect for the Tower’s cultural and ceremonial significance, is widely observed though not legally mandatory.

Vedauwoo

Every complaint climbers make about Vedauwoo is a mineral property of the Sherman Granite, 1.43 Ga, coarse and K-feldspar-porphyritic — 54% of the rock is feldspar, in crystals one to three centimetres across. Feldspar cleaves on two planes at nearly 90°, so as it disintegrates it breaks into blocky fragments with straight sharp edges instead of rounding off the way quartz does. A rock that is half centimetre-scale feldspar, coming apart grain by grain, is a rock covered in small blades: it shreds skin, and it grips like nothing else.

The offwidths are not a local eccentricity either. A massive, monolithic granite with a widely spaced east-northeast joint set does not give you a hundred hairline seams; it gives you a few big splits through a big block. And the famously flaring, insecure jams are a fossil of how these tors formed: they weathered underground, groundwater rotting the rock along fractures until the intact corestones were left to be exposed later. The joint faces are chemically etched and rounded near the surface, where water sat longest, and stay tight and square deep inside. Jam deep, expect cams to walk outward in the flare, and tape everything.

Area	Near	Rock	Style	Size	Grades	Notes
Vedauwoo	Laramie (~15–25 min E, off I-80)	Sherman Granite, 1.43 Ga — coarse and K-feldspar-porphyritic, ~54% feldspar	Trad — wide cracks and offwidths, also face and bouldering	1,000+ routes	5.0–5.14, widely sandbagged	Turtle Rock and the Nautilus are the standout sub-areas; short approaches at ~8,000 ft. Medicine Bow–Routt National Forest.

Laramie area

Area	Near	Rock	Style	Size	Grades	Notes
Vedauwoo	Laramie	Granite	Trad	See above	See above	The area’s headline destination.
Snowy Range (Medicine Bow Peak area)	Laramie (~45 min W)	Medicine Peak Quartzite, 2.4–2.0 Ga — quartzite, not granite; this census previously had both	Alpine slab and face, short multipitch	Not independently confirmed	Moderate, generally sub-5.10	Starts ~10,500 ft; short season mid-June–mid-September.

Fremont Canyon / Dome Rock (Casper area)

All three areas here sit on the Granite Mountains / Sweetwater arch — a Laramide uplift that did something unusual: it collapsed, was buried by its own basin fill, and was then dug back out in what Wyoming geologists call the Great Exhumation. The rock is Archean, a 2.86 Ga metamorphic complex intruded by a 2.55 Ga biotite granite. (Some local material calls Independence Rock 1.5 billion years old; the weight of the evidence is Archean, and that figure looks like a confusion with the Sherman Granite two ranges east.)

Fremont Canyon is the North Platte cutting clean through to basement, exposing the Great Unconformity in a gorge rather than on a mountain front — and its walls were, until recently in geologic terms, the bed and banks of that river. “Water-worn” is the word every source uses, and it means abraded, polished and undercut: friction lower than a normal granite crag, rounded crack lips that want gear placed deep, and a base that is the river itself, which is why so many routes are rappelled into from the rim.

Area	Near	Rock	Style	Size	Grades	Notes
Fremont Canyon	Alcova (~30 min from Casper)	Water-worn Archean granite, ~2.55 Ga, in a gorge cut to basement through the Great Unconformity	Sport, trad, mixed	~180+ routes	5.6–5.13	Many routes reached by rapping from the rim; The Blade is a signature 95-ft detached tower. All-paved access, free to climb.
Dome Rock	Casper area (Pedro Mountains)	Archean granite of the same basement block (inferred)	Slab and friction climbing, beginner-friendly	Not stated	Gentle grades	No longer blank: BLM, on the Seminoe–Alcova Backcountry Byway, 7,116 ft, climbing on the west side, gentle exfoliation slabs. Access caveat: a rancher owns several acres around the dome itself — ask.
Independence Rock	Casper area (~60 mi SW)	Archean granite exfoliation dome (some local sources say 1.5 Ga; the evidence says Archean)	Scrambling/low-grade, historic site	Not a technical destination	—	Emigrant-trail landmark first, noted for completeness.

Wind River Range (alpine)

The biggest exposure of Archean crust in the state — roughly 80% of the range is late Archean granitoid, dominated by the Bridger, Louis Lake (~2.63 Ga) and Bears Ears (~2.5 Ga) batholiths. The single most useful thing to know here is that the range is two rocks, north and south. The southern Winds — Cirque of the Towers, Deep Lake, Haystack, Big Sandy — are homogeneous granitoid: uniform, predictable, well-jointed, and the Cirque’s shape is simply that joint pattern made visible by ice plucking along it. The northern Winds — Titcomb, Gannett, Dinwoody — are gneiss with granite intruded into it, heterogeneous at outcrop scale. The American Alpine Club’s own reconnaissance puts it memorably: if Cirque rock is vanilla ice cream in its uniformity, Titcomb rock is many-flavoured. Expect the quality to change within a pitch up there, and expect the named hazard to be the ledges and talus rather than the routes.

Area	Near	Rock	Style	Size	Grades	Notes
Cirque of the Towers	Lander / Pinedale (10+ mi backpack in)	Late Archean granitoid — uniform and well-jointed; the Cirque’s shape is that joint pattern, plucked out by ice	Alpine, multipitch trad	Dozens of named lines across ~15 peaks	5.4–5.11+, classics 5.6–5.9	Includes two 50 Classic Climbs: East Ridge of Wolf’s Head, Northeast Face of Pingora. Peak season July–August; Bridger and Popo Agie Wilderness permit logistics apply.
Deep Lake / Haystack Mountain area	Pinedale (via Big Sandy TH)	The same late Archean granitoid	Alpine multipitch	Fewer than the Cirque but notable	Moderate–5.9-ish	Shorter approach (~5.5 mi) than the Cirque; common warm-up basin.

Tetons (alpine rock)

Young mountains of very old rock. The basement is about 2.7 Ga — complexly deformed layered gneiss, the Webb Canyon Gneiss, and the non-foliated Mount Owen Quartz Monzonite at ~2.55 Ga, all cut by undeformed diabase dikes including the Black Dike that stands 200 feet proud of Mount Moran’s face. The range itself is young: a normal fault on its east side began slipping 13 to 7 Ma, has moved most in the last 2 Ma, and has put 6 to 9 km of relative displacement between the range block and Jackson Hole. Glaciers then cut Cascade, Death and Garnet canyons as troughs, plucking their walls clean along joints.

Which explains the honest local summary — rock quality ranging from dreamy to nightmare within a single pitch. An interlayered gneiss complex intruded by a discordant pluton and cut by dikes has four or five different rocks on one face, and the classic routes wander because the good rock wanders. The Mount Owen Quartz Monzonite is the good rock: massive, uniform, clean cracks and reliable gear. The layered gneiss gives the incut holds that make 5.4 to 5.8 possible on a peak that size — and the detached flakes and loose ledge blocks. One footnote for the collectors: the Death Canyon Limestone is a formally named member of the Cambrian Gros Ventre Formation, named for the canyon climbers climb in.

Area	Near	Rock	Style	Size	Grades	Notes
Grand Teton (main massif)	Jackson / Moose	Archean layered gneiss and ~2.55 Ga Mount Owen Quartz Monzonite, cut by diabase dikes	Alpine multipitch trad	Numerous named routes	5.4 (Owen-Spalding) to 5.8+ (North Ridge)	Upper Exum Ridge is likely the most-climbed technical route to the summit; permits/registration required in the park’s backcountry.
Cascade Canyon and other Teton cragging	Jackson / Moose	Gneiss and quartz monzonite, in glacial trough walls plucked clean along their joints	Multipitch cragging	Not independently confirmed	—	Good non-summit multipitch terrain within the park (not itemized further this pass).
Blacktail Butte	Moose	Limestone — unit genuinely unresolved: the butte carries both Paleozoic carbonate and soft Miocene Teewinot lake limestone, and no source names which the crag is on	Sport	~20 routes across three walls	Mostly 5.10–5.12	Added by the geology pass. Technical, polished climbing — footwork over strength, and slick in humidity.

Jackson area crags

This is a different tectonic province from everywhere else in this chapter. Everything east of Jackson is Laramide, basement-cored, thick-skinned. The Hoback and Snake River canyons are in the Sevier fold-and-thrust belt — thin-skinned and older, where whole sheets of Paleozoic rock were shoved eastward over Mesozoic rock. The Absaroka thrust puts Mississippian Madison Limestone on top of Cretaceous strata, and these crags ride that upper plate. Rodeo Wall’s diagnostic description — rock that “seems to alternate between either polished or super-sharp” — is the signature of thin-bedded carbonate: hard fine-grained beds polish, more fossiliferous beds weather to razor edges. So holds come in horizontal bands because the beds do, and a bolt is only as good as the bed it is in.

Area	Near	Rock	Style	Size	Grades	Notes
Rodeo Wall	Hoback Junction (~10 mi S of Jackson)	Thin-bedded Paleozoic carbonate on the Absaroka thrust sheet — probably Madison Limestone (inferred)	Sport, mostly vertical with some slab	~12 routes	5.9–5.11	East-facing; good evening/hot-day option, ~10 min approach.
Hoback Shield and other Hoback-corridor crags	Hoback Junction	Limestone	Sport	Not independently confirmed	—	Named as a sub-area near Rodeo Wall; no independent route count found (unverified).

Cody area (limestone sport + ice heritage)

Shoshone Canyon is the whole of Wyoming geology in three miles. The North Fork has cut the Rattlesnake Mountain anticline, exposing Archean granite and granitic gneiss more than 2.7 billion years old beneath 515-million-year-old Flathead Sandstone — the Great Unconformity on glorious display from the dam — with the tilted Paleozoic section above. That sorts the climbing: the limestone sport crags are on the north side of the road on Rattlesnake Mountain, the granite trad areas are at the west end near the tunnels and down by the river, and the bouldering is on sandstone. Same division as Sinks Canyon and for the same reason — crystalline rock cracks, carbonate pockets. Expect the limestone here to have dipping bedding, since it sits on a steeply tilted anticline limb: holds and ledges run at an angle across the wall.

The South Fork’s ice is the best “why does this area exist” story in the state. The Absaroka volcanic pile is thousands of feet of flat-lying, alternating volcaniclastic units, and it erodes into a stepped cliff profile — every resistant band is a lip, every lip is a waterfall, and every waterfall in a cold dry Wyoming winter is an ice route. The densest concentration of frozen waterfalls in the continental US exists because a volcanic pile is layered. The corollary is the hazard: the rock behind the ice is breccia that locals call kitty litter, so rock protection is poor to useless and warm spells bring the cliff down.

Area	Near	Rock	Style	Size	Grades	Notes
Shoshone Canyon	Cody	All three, and now located: limestone sport crags on the north side on Rattlesnake Mountain, granite trad at the west end near the tunnels and by the river, sandstone bouldering	Sport, trad, bouldering	Hundreds of routes	Beginner to expert	West of town on Rattlesnake Mountain; greatest variety of rock and style in the region.
South Fork of the Shoshone (ice)	Cody (~35–40 mi SW)	Ice on benches of Absaroka volcaniclastic rock — the rock behind it is breccia locals call kitty litter	Ice and mixed climbing	One of the densest concentrations of ice routes in the continental US	WI3–WI6+/M-grades	Legendary proving ground associated with Stan Price, Alex Lowe, Mark Twight, Steve House, and Aaron Mulkey. Winter season only.

Sheridan / Bighorns (Story area, Eastern Bighorns)

The same range as Ten Sleep, opposite flank. On the east side of the Bighorn uplift the Paleozoic carbonate is tilted eastward off the Archean core, and the creeks draining to the Powder River Basin — South Piney, Tongue, Crazy Woman — have cut canyons across it. Same Madison and Bighorn carbonate, same pockets, same seepage, and the same caution about solution-breccia bands.

Area	Near	Rock	Style	Size	Grades	Notes
South Piney Creek Canyon (Story Canyon)	Story	Madison and Bighorn carbonate off the Bighorns’ east flank	Sport, creekside to steep technical headwalls	Not independently confirmed, but “the premier sport crag of the Eastern Big Horns”	5.10–5.12 concentration	Easy access, wide range of terrain.
Tongue River Canyon	Dayton/Sheridan	Limestone	Sport, some trad	Not independently confirmed	—	Active development area alongside Story Canyon (unverified).
Crazy Woman Canyon	Buffalo	Limestone	Sport, some trad	Not independently confirmed	—	Same caveat as Tongue River Canyon (unverified).

Sweetwater Rocks / Lankin Dome

Archean granite, 2.6 to 2.8 Ga, standing as exfoliated domes out of a plain of young sediment — which is the Great Exhumation in one image, since that sediment is the stuff that used to bury them. The climbing follows from the landform: an exfoliation dome’s only fractures are sheeting joints parallel to its surface, and those are underfoot rather than in front of you, so there is nothing to put gear in between them. Hence a seven-pitch 5.5-to-5.9+ classic described as runout slab with crystal holds. The crystals are the medium — with no cracks and no pockets, the holds are phenocrysts and the differential weathering around them. Devils Gate nearby is a water gap: the Sweetwater held its course while the granite ridge rose across it, and sawed through.

Area	Near	Rock	Style	Size	Grades	Notes
Lankin Dome	Jeffrey City (~10 mi E)	Archean granite, 2.6–2.8 Ga — reddish from iron oxidation of its biotite and hornblende	Trad multipitch	A handful of long lines; Sky Route (7 pitches) is the benchmark	5.5–5.9+ on the Sky Route	Very remote — roughly an hour’s approach; Sweetwater Rocks Wilderness Study Area (BLM). Mixed public/private land — respect fences and gates. The Lankin Gap approach closes seasonally (roughly March–June) for livestock grazing.
Devils Gate (Sweetwater Rocks)	Jeffrey City area	The same Archean granite (inferred)	Trad	Not independently confirmed	—	Named sub-area on Mountain Project; no further detail confirmed (unverified). The gate is a water gap — the Sweetwater held its course while the ridge rose across it.

Guernsey State Park / Hartville uplift

This chapter’s introduction has always mentioned Guernsey’s south-facing limestone and then never listed it — the worst of both worlds. The geology pass found a real, named route inventory, and a reason for real caution.

Area	Near	Rock	Style	Size	Grades	Notes
Guernsey State Park	Guernsey	Madison Limestone and the cherty Guernsey/Hartville Formations of the Hartville uplift	Sport and toprope, much of it on home-made fixed gear	Named sectors: Red Clove Wall, Red Cloud Wall, The Center Slab, The Rev Wall	Not stated (Fun Hog is 90 ft)	Read before going. Mountain Project warns that much of the climbing here is on fractured or unsound rock protected by home-made anchors and bolts, and that holds and placements which look sturdy may not be. That is structural, not accidental: the Hartville uplift is a small, tightly folded Laramide structure with steep dips, and steeply dipping folded limestone — with chert in it, which shatters where limestone bends — is fractured limestone. Helmet, judgement, and no assumptions about fixed gear.

Areas checked but not confirmed as climbing destinations

The geology pass could not turn any of these three into climbing areas. It could explain two of them.

• Baggot Rocks (Carbon County) — still no evidence of an established route inventory; every source treats it as a fishing-access and geology site. But the rock now has a name and a date, and a nice one: the Baggot Rocks Granite, 2340 ± 50 Ma, of which this outcrop is the type locality. Massive to foliated granite cut by diabase dikes and pegmatite, forming prominent rounded outcrops — tor-and-dome habit, so exfoliation slabs and crystal faces with few continuous cracks if anyone ever develops it.
• Glendo State Park — the absence is consistent with the rock. This is gently dipping, cherty, thin-bedded Mississippian–Pennsylvanian carbonate (the Guernsey and Hartville Formations, source of the agate and jasper collected around the reservoir) over an Archean core: a ledge-and-slope landscape, not a cliff landscape. Nothing here is the massive 500-foot cliff-former the Madison is on the Bighorn rim.
• Flaming Gorge / Green River (WY side) — here the absence of climbing is a rock-quality fact rather than a research gap. Firehole Canyon’s cliffs and spires are Mancos Shale capped by Mesaverde sandstone, with bits of the lacustrine Green River Formation: soft shale under thin ledge-forming sandstone erodes into hoodoos and badlands. Spectacular, structurally rotten. Hoodoo country, not crag country.

Guidebooks

Title	Author(s)	Area covered	Notes
Ten Sleep Canyon Climbing, 2nd ed.	Louie Anderson	Ten Sleep Canyon	Wolverine Publishing.
Devil’s Tower Climbing (2019)	Zach Orenczak and Rachael Lynn	Devils Tower	Referenced by 57hours and climbing-media coverage.
Rock Climbing Jackson Hole & Pinedale, WY	Not independently confirmed	Jackson Hole / Pinedale	Title confirmed via climbingwyoming.com; author unverified this session.
Fifty Classic Climbs of North America	Steve Roper and Allen Steck	Multi-state	Not Wyoming-specific but the standard reference for the state’s most-cited alpine and crack classics (Durrance, Grand Teton routes, Wolf’s Head, Pingora).
Lander-area (Wild Iris / Sinks Canyon) guidebook(s)	Not independently confirmed	Lander area	Wild Iris Mountain Sports (wildirisclimbing.com) is the standard on-the-ground reference; no dedicated print title/author confirmed this session.
Vedauwoo guidebook(s)	Not independently confirmed	Vedauwoo	vedauwoo.org is the standard modern online reference; no current print title/author confirmed this session.