41.492660, -113.920247 (approximate)
Geodes containing calcite, quartz, and agate/chalcedony.
I’ve not seen any published on this site — print, internet, or otherwise. Nonetheless, it’s a perennial favorite of rockhounds in northern Utah, southern Idaho and western Nevada.
Known for their distinctive red rhyolite shells and highly variable innards, they are a fairly accessible and gratifying reward for a day trip. Although most of the geodes have a thin quartz layer lined with white botryoidal calcite and yellow barite, there are often surprises to be found within. Formations of banded agate, black bladed crystals (not sure what these are — possibly axinite), and occasionally well-terminated quartz crystals are present.
The site is located on Winter Cabin Road, which is a left turn off of the main gravel road heading north to Grouse Creek proper. The road winds back into the foothills and the geode bed is on the north side of the road just below the western crest of a large hill. Unfortunately, I don’t have any site photos at this time, but I’ve verified the Google Maps coordinates from my memory. A lot of broken material can be found scattered around on the hillside, but take a good shovel and dig down a foot or two to find better specimens. As always, make sure to fill in you holes.
You can approach from a couple of different directions and road conditions are variable with the time of year. Generally I would recommend a high-clearance/4×4 vehicle in every case. There is private property for grazing and claims in the area, so be sure to respect that and close the one or two gates you will encounter.