Unnamed Thermal Spring
This unnamed 77°F spring flows 23.9 degrees above the 53.1°F ambient temperature near Plain City in Weber County, emerging at 4,210 feet on state-managed Great Salt Lake lands. Water chemistry shows extreme mineralization: 24,900 mg/L TDS with 13,100 mg/L chloride—reflecting proximity to the hypersaline lake. The spring sits 140 meters from South East Promontory Road, requiring a short walk.
The spring occupies shoreline habitat along the Great Salt Lake, North America's largest terminal lake. At 4,210 feet elevation, the setting receives 14.2 inches of annual precipitation and 24.3 inches of snow. Vegetation includes salt-tolerant species: pickleweed, saltgrass, and iodinebush. The lake's water level fluctuates dramatically with precipitation cycles, periodically inundating or exposing spring sites. The Promontory Mountains rise to the north; Wasatch Range lies east.
No name is recorded for this spring. The Great Salt Lake region was utilized by Shoshone peoples. Euro-American exploration intensified after 1847 with Mormon settlement. The Promontory area gained fame in 1869 when the transcontinental railroad was completed nearby. This spring sits on School and Institutional Trust Lands Administration (SITLA) property—state lands managed for revenue generation.
Access status is unclear (listed as "Unknown"); verify permissions with SITLA before visiting. The 140-meter walk crosses variable terrain depending on current lake levels. Extremely high salinity (24,900 mg/L TDS) makes the water unsuitable for most uses. Simpson Springs Campground, 35.4 kilometers south along the Pony Express Trail, offers developed camping. Visit spring or fall for moderate temperatures.
Is this spring worth visiting?
Best for
- Overnight camping trips
- Mineral-rich therapeutic bathing
The water at This spring contains 24900 mg/L total dissolved solids. It is notably rich in chloride (natural antiseptic with skin health benefits) and total dissolved solids (higher mineral concentration for therapeutic soaking).
Overview The campground is situated on the eastern edge of Utah's West Desert near the historic Simpson Springs station on the Pony Express National Historic Trail. Simpson Springs was the site of a significant Civilian Conservation Corps (CCC) camp in the late 1930s and early 1940s, just prior to the establishment of the US Army Dugway Proving Grounds during World War II. Recreation Hiking, picnicking, OHV riding, mountian biking, horseback riding, wildlife viewing, scenic backcountry byway,...