Lander

Lander is a small city of under 8,000 wedged against the southern Wind River Range, bordering the Wind River Indian Reservation, and it is the closest thing this corridor has to a purpose-built climbing town. Two areas anchor it: Sinks Canyon, which starts at the edge of town and runs southwest through three distinct rock zones — desert sandstone low down, limestone/dolomite through the middle, granite up top — and Wild Iris, a high, sun-baked dolomite complex about thirty minutes further southwest near South Pass, sitting at roughly 9,000 feet. Newer satellite crags — Fossil Hill, the Sweat Lodge, remote Wolf Point — round out the current guidebook.

The town’s climbing identity is really one man’s legacy. Todd Skinner moved to Lander in 1989–90 after hearing about the dolomite nearby, began developing what became Wild Iris, and opened Wild Iris Mountain Sports with Amy Skinner in 1990 to support the community growing around it. In the early 1990s Skinner and friends founded the International Climbers’ Festival, still running today and billed as the longest-continuously-running climbers’ festival in the country. Skinner died in a rappelling accident on Yosemite’s Leaning Tower in 2006; the shop and the festival he started both carry on. Lander is also international headquarters for NOLS, giving the town a second, older outdoor-education identity that runs alongside its climbing one.

Plate reserved — hand-drawn map & photographs to come

The rock

Lander sits at the southeastern nose of the Wind River Range, a Laramide basement-cored uplift whose Archean core was driven northeast over the Wind River Basin — cooling underway by 75 Ma, fastest between 60 and 57. Everything about the local climbing follows from that one fact, because it tilted the whole Paleozoic section off the flank of the range. Drive up Sinks Canyon and you drive down the section and back in time: within a few miles the rock goes from sandstone to carbonate to granite. Every crag around town is a bench on that tilted stack, or the basement beneath it.

At Sinks the order, top of the section to bottom, is Tensleep Sandstone (exposed from the canyon mouth), Amsden, Madison Limestone, Bighorn Dolomite, Gallatin Limestone, Gros Ventre Shale, Flathead Sandstone, and then Precambrian granite and banded iron formation at the head of the canyon. One number to distrust: the local interpretive material calls that granite “over 4 billion years old.” It is not. The oldest dated rock in the Wyoming Province is 3.5 Ga, the Wind River batholiths are 2.63 Ga (Louis Lake) and about 2.5 Ga (Bears Ears), and nothing anywhere on Earth is reliably older than about 4.03 Ga.

Three rocks in one canyon

The sandstone low down is the Pennsylvanian Tensleep — eolian dune sand, cross-bedded, giving crack systems along joints and flakes parallel to the cross-beds. “Sandy sandstone” is the climbers’ word for it, and it is a warning: eolian sandstone is quartz grains in a small volume of cement, so give it a day or more after rain before you load a hold or a piece of gear.

The carbonate through the middle is the Madison and the Bighorn, and it is where Killer Cave, Scud Wall, The Wilds and the rest are. It gives the pockets, the caves, the steep bulges — and the seepage, because carbonate drains through itself and a limestone crag weeps for days after the sagebrush is dry. Killer Cave, incidentally, is a genuine solution feature rather than a metaphor, and its shelter is a real advantage in a canyon that collects afternoon thunderstorms. The Sinks themselves are the same plumbing at full scale: the Middle Fork of the Popo Agie vanishes into a cavern in the Madison and reappears at the Rise a quarter-mile down-canyon — taking over two hours to travel it, by dye test.

The granite at the top is Archean granitoid of the Wind River batholith complex, most plausibly the 2.63 Ga Louis Lake batholith, though no source names the pluton at the crag. Rock that has been weathering for two and a half billion years gives rounded crystals, gritty friction, grus, and flakes that ring hollow.

Wild Iris, and where the monos come from

Wild Iris is Bighorn Dolomite — bone-white, massive, siliceous, Middle-to-Late Ordovician, the “miles of bone-white Bighorn Dolomite” that line the southern Wind Rivers west of town. The formation’s middle massive member here is under 150 feet thick, which is exactly the right scale for these walls. (Our own earlier notes filed Wild Iris under the Madison Group; no source we could reach supports that, and the local sources say Bighorn.)

Then the pockets. Stand at the base and you can find 150 monos on any section of cliff, and the local story is that they are gas bubbles. They are not — this is sedimentary rock, and the real mechanism explains how the crag behaves. Dolomitization shrinks the rock’s bulk volume by about 13% as small magnesium ions replace larger calcium ones, opening intercrystalline porosity and giving crystalline dolomite its sugary texture; fossils, ooids and burrow fills then dissolve preferentially into vugs; and karst enlarges joints and partings into cavities. So pockets sit in horizons and clusters aligned on the fabric of the rock — read the band, not the wall. Their rims are freshly dissolved crystal terminations, which is why new pockets so often have that razor lip. And a sugary, porous dolomite is strong in compression and weak in tension at its surface: pocket rims break, whole pockets rarely do. Bolts hold well in the massive siliceous rock and badly in a vuggy band, which is why glue-ins have become the local norm.

Aspect explains the calendar. Wild Iris faces south at about 9,000 feet, so it is the summer crag; Sinks, 1,500 feet lower and minutes from town, takes the shoulders. Baldwin Creek’s dolomite faces due south and bakes in July but climbs the cold edges of the year — when the road is open, since it closes in winter for elk habitat. And the Sweat Lodge is worth a geologist’s second look: it is a massive dolomite flake that toppled off the cliff and wedged against it, forming an A-frame you climb inside. A carbonate cliff fails along its vertical joints, and where the slab leans instead of shattering you get exactly that. Two cautions the guidebooks do not print: a leaning flake is held up by friction and geometry rather than by attachment, and the floor inside it is the debris cone from its own collapse.

Chosen moderates

This is the richest record in this chapter: thirteen named moderates turned up with grade and sector confirmed, more than any other page in the Corridor so far. Descriptive detail is search-grounded rather than pulled from a live Mountain Project session, so treat sector placement as good but not final.

Route	Grade	Sector	Notes
La Vaca Peligrosa	5.8	OK Corral, Wild Iris	Pocket-pulling beside a crack; called “the absolute best, easy, pure, pocket pulling climb anywhere.”
Frogger	5.8	The ZoZone, Sinks Canyon	Stem a corner between the main wall and a giant flake, then the blunt arete to an anchor above a small roof.
Action Candy	5.9+	Killer Cave (curtain wall), Sinks Canyon	One of the easier vertical lines flanking Killer Cave’s harder cave routes.
Earth A.D.	5.9	The Wilds, Sinks Canyon	A classic on a southwest-facing wall with morning shade.
Heatseeker	5.9	Scud Wall, Sinks Canyon	Popular, sometimes-crowded sub-5.10 sector.
Dogtown	5.9	Sinks Canyon (sector unconfirmed)	~45 ft; confirm exact sector before publishing.
Claim Jumper	5.10c	OK Corral, Wild Iris	Slabby footwork into an overhanging finish; well bolted, approachable for the grade.
Take Your Hat Off	5.10b	Wild Iris (Hot Tamale Wall area, unconfirmed)	Technical start into big, juggy pockets on vertical-to-slightly-overhanging rock.
Manifest Destiny	5.10	Sinks Canyon (sector unconfirmed)	Listed as a canyon classic; sub-grade and sector unverified.
Sandman	5.10c	The Wilds, Sinks Canyon	A Wilds classic.
Elmo’s Fish	5.10d	Killer Cave (curtain wall), Sinks Canyon	Vertical-angle line on the curtain wall flanking the main cave.
Candy Man	5.10d	The Wilds, Sinks Canyon	A Wilds classic.
Easy Ridin’	5.10d	Rode Hard Wall, Wild Iris	Described as one of the most popular moderates at Wild Iris.

Season & logistics

Sinks Canyon, lower and closer to town, climbs earlier and later in the year than Wild Iris; Wild Iris itself runs roughly June through October at 9,000 feet, with pleasant but changeable summer weather — plan around chasing shade on its sun-facing walls. Combined, area marketing claims some 320 climbable days a year. Lander City Park offers free camping in town for up to three nights, 28 tent sites and 7 RV sites, walking distance to downtown. Wild Iris Campground (Shoshone National Forest) sits near the crag and began charging $10/night in 2024 after years of being free. Fossil Hill carries a voluntary raptor closure roughly June 9–August 15; check current dates with Wild Iris Mountain Sports (166 Main Street), the town’s climbing-shop hub for gear and conditions.

The book to buy

Steve Bechtel et al., Lander Rock Climbs 2023 (Climb Strong, 1st ed.) — the current standard guidebook, 304 pages covering 1,700+ routes from 5.2 to 5.15a across Sinks Canyon, Wild Iris, Fossil Hill, the Sweat Lodge and more; author credit varies slightly across retailers and is worth confirming on the copy in hand. Pair it with Mountain Project’s Lander Area pages for current beta, and check Wild Iris Mountain Sports for seasonal closures and the Shoshone National Forest for campground fees before you go.