File:Seminoe Mountains (Wyoming, USA) 5.jpg

English: Some geologic localities are harder to reach than others. The easiest are roadcuts. The most difficult include remote mountain sites.

Seen here are the Seminoe Mountains in south-central Wyoming. The range is cored by Precambrian basement rocks (igneous and metamorphic rocks). Structurally-tilted Phanerozoic sedimentary rocks occur along the southern flanks of the mountains. The northern margin of the range is bounded by a major fault. Thrust faulting occurs in the southern and southwestern Seminoes.

The mountains are part of the Central Rockes (= Middle Rockies) and were uplifted during the Laramide Orogeny in the late Mesozoic and early Cenozoic.

This view is of the northern margin of the Seminoes. I was interested in seeing and collecting Precambrian komatiites (I love rare rocks). This is a Bureau of Land Management road, which goes to the mouth of the canyon I was interested in. The road's condition was lousy early on and soon became impassable. Walking from there on. Turns out is was a 6.25 mile hike, one-way. So a total of ~12.5 miles. Was not prepared for that. Did reach the locality, finally. Did return to the vehicle and civilization, eventually. I call such hikes "death marches". I've had three memorable death marches over the years: 1 in the Bahamas, 1 in Montana's Beartooth Mountains, and here. For hard-core hikers, 12.5 miles isn't much, but I'm a simple geologist.

Here are some of my notes from that day, for entertainment purposes: "Starting at 12 noon, hiked west along dirt road - the Death March. Got fatigued. Tempted to turn back, but wanted something to show for the long hike. Another gully, another gray hair. Took drinking water, but not enough to be comfortable in the end. Finally reached the mouth of Sunday Morning Creek Canyon in the late afternoon. The outcrop was about a mile south of there. Didn't have much time to look around. . . . Indiana Jones and the Lost Komatiite. Highway to Hell Canyon. Highway to Hell Metakomatiite."

Locality: looking ~west from Bureau of Land Management 3104 Road (BLM 3104 Road), northern margin of the Seminoe Mountains, northern Carbon County, south-central Wyoming, USA

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Example references:

Hausel (1994) - Economic geology of the Seminoe Mountains Mining District, Carbon County, Wyoming. Wyoming State Geological Survey Report of Invetigations 50. 31 pp. 2 pls. (mountainscholar.org/bitstream/handle/20.500.11919/5625/ws...)

Blackstone & Hausel (1992) - Field guide to the Seminoe Mountains. Geological Survey of Wyoming Reprint 48. 10 pp. [paginated 201 to 210] (mountainscholar.org/bitstream/handle/20.500.11919/5666/ws...)