Where to Find Jasper in Wyoming

Wyoming jasper is concentrated in the Wind River Range foothills and the Owl Creek country. The Wiggins Fork drainage in Fremont County produces red and brown picture jasper in welded tuff, and the Sheep Mountain area in Albany County yields ribbon and brecciated jasper in fault zones. The Granger and Eden Valley districts in Sweetwater County add jaspered petrified wood and oolitic jasper from Eocene lake beds. Smaller showings of dendritic jasper turn up along the Powder River breaks. Most Wyoming jasper is dense and takes a glassy polish, so cabbing material is widely sought even when surface float is small. The most productive ground is in Wiggins Fork (Fremont County), Sheep Mountain (Albany County), Granger and Eden Valley (Sweetwater County).

Casual hand collection of common rocks and minerals like jasper is allowed on most BLM and U.S. Forest Service land in Wyoming, with daily and annual limits set by the local field office. National parks, most state parks, and tribal land are off-limits. Always confirm rules before a trip.

Wiggins Fork (Fremont County) is the standout. Other strong ground includes Sheep Mountain (Albany County), Granger and Eden Valley (Sweetwater County).