Fumarole Butte
Fumarole Butte is a warm spring on open BLM land in Millard County, twenty-two miles from Delta. It is about as roadside as a spring gets, thirteen feet from the road. The water is tepid, low seventies, and there is no chemistry on file. The record has no USGS site number for it either.
Managed by the Fillmore Field Office, this sits above five thousand feet in dry basin country, seven inches of rain in an ordinary year and a light snow season. You park and you are there. Jericho Campground and Picnic Area is the nearest camping listed, about 24 miles away.
Best months per the record are the winter ones. Open access, no fee noted. One reading supplies the temperature and there is no sample, so the warmth is unverified. Delta is the resupply town. The record is silent on a pool or any structure. Public land, no permission required.
One of 4 campgrounds within the Little Sahara Recreation Area (LSRA), the Jericho Campground and Picnic Area has 16 sites for camping and/or picnicking. On busy weekends in the spring, LSRA may receive up to 30,000 visitors, large camping groups, and heavy use of public facilities.