Big Warm Springs

Tooele County County, Utah · Near Grantsville
40.7430°N, 112.6420°W · 4,220 ft
72°F 4,220 ft Open Roadside SLB Camping nearby (17.5 mi)

Big Warm Springs flows at 72°F on Utah State Trust Lands in Tooele County near Grantsville at 4,220 feet elevation within the I-80 Block Special Recreation Management Area. Recent USGS measurements show highly saline water with extraordinary total dissolved solids of 8,110 mg/L, including sodium at 2,750 mg/L and chloride at 4,420 mg/L, creating brine-like water reflecting circulation through ancient evaporite deposits.

The spring emerges in the broad Tooele Valley west of the Stansbury Mountains, whose peaks rise dramatically to elevations exceeding 11,000 feet immediately south and east. The valley floor sits in rain shadow, receiving just 12.3 inches of precipitation annually with moderate snowfall (22.5 inches). Sagebrush and salt-tolerant vegetation dominate the landscape, while seasonal wetlands and playas reflect the basin's internal drainage. Interstate 80 crosses the valley several miles north, connecting Salt Lake City to Nevada across the Great Salt Lake Desert.

History of Big Warm Springs

The name simply describes the feature's size and temperature. Historical use likely centered on cattle ranching and perhaps salt extraction given the extreme brine chemistry. State Trust Lands historically served to fund Utah's public schools through lease revenues from grazing, mining, and other extractive uses. The area lacks documented hot springs resort development despite the thermal feature. Access remains open though the Wikipedia entry appears to describe a different California spring (Slates Hot Springs), indicating database confusion.

Access via dirt roads passable to most vehicles in dry conditions. The roadside location (73 meters from road) provides easy walking. The water is too saline for comfortable soaking and may irritate skin. Visit spring or fall when temperatures moderate; summer heat can exceed 95°F while winter brings freezing conditions. Lower Narrows Campground in South Willow Canyon (28 kilometers southeast) offers developed facilities. Combine with exploration of the Stansbury Mountains or Great Salt Lake Desert salt flats to the west.

Is Big Warm Springs worth visiting?

Best for

  • Easy day trips
  • Overnight camping trips
  • Mineral-rich therapeutic bathing
Big Warm Springs is well suited for easy day trips and overnight camping trips.
Monthly Climate
29°
Jan
34°
Feb
44°
Mar
52°
Apr
61°
May
73°
Jun
82°
Jul
80°
Aug
70°
Sep
55°
Oct
42°
Nov
31°
Dec
Annual Precip: 12.3 in Annual Snow: 22.5 in
Best Time to Visit
January Air 29°F · Water 72°F · +43° contrast
December Air 31°F · Water 72°F · +41° contrast
February Air 34°F · Water 72°F · +38° contrast
January offers 53°F more contrast than July
USGS Field Measurements
Recent Temperature 64.9°F (18.3°C) Measured May 27, 1966
Water Chemistry Sampled 1966-05-27

The water at Big Warm Springs is slightly alkaline (pH 7.7) with 8110 mg/L total dissolved solids. It is notably rich in calcium (may support bone density and joint health), magnesium (known for muscle relaxation and stress relief), and sodium (supports circulation and skin hydration).

pH 7.7 Slightly Alkaline
pH influences mineral absorption through skin
Higher mineral concentration for therapeutic soaking
Calcium 140 mg/L
May support bone density and joint health
Magnesium 85 mg/L
Known for muscle relaxation and stress relief
Sodium 2,750 mg/L
Supports circulation and skin hydration
Sulfate 318 mg/L
Traditionally used for skin conditions and inflammation
Chloride 4,420 mg/L
Natural antiseptic with skin health benefits
Nearby Camping
Lower Narrows Campground 17.5 mi away

Overview Upper Narrows Campground is located southwest of Grantsville, Utah, in South Willow Canyon at an elevation of 6,840 feet. Visitors enjoy exploring local trails. Recreation The multi-use Stansbury Front and Medina Flat Trails begin nearby, offering access to the rugged Deseret Peak Wilderness. Willow Creek offers rainbow and brown trout fishing. Facilities This campground has 3 single sites. This campground has vault restroom facilities. There is no water system in this campground, yo...

Reservable Yes
Reserve on Recreation.gov →
What to Bring
Swimsuit & towel
Water bottle Stay hydrated, especially in hot water
Camping gear Nearby camping at Lower Narrows Campground
Trash bag Pack out what you pack in
References
USGS Quad: TIMPIE 15 · PP 492: 9.0 · NOAA: 2.0 · AMS Map: TOOELE
Frequently Asked Questions
What is the water temperature at Big Warm Springs?
Big Warm Springs has a water temperature of 72°F (22°C). This is a warm thermal spring.
Where is Big Warm Springs located?
Big Warm Springs is located in Tooele County, Utah at 4,220 feet elevation, near Grantsville. Coordinates: 40.7430°N, 112.6420°W.
How do I get to Big Warm Springs?
Big Warm Springs has Roadside road access (238 ft from the road).
Is Big Warm Springs free to visit?
Big Warm Springs has Open access. It is managed by SLB.
Can I camp near Big Warm Springs?
Yes, Lower Narrows Campground is located nearby (17.5 miles away).
What minerals are in the water at Big Warm Springs?
Water chemistry analysis shows the presence of pH, Total Dissolved Solids, Calcium, Magnesium, Sodium, Sulfate, Chloride. The pH is 7.7 (slightly alkaline). Total dissolved solids measure 8,110 mg/L.
Is it safe to soak at Big Warm Springs?
Big Warm Springs is generally safe for soaking at its recorded temperature. Always tell someone your plans before visiting remote hot springs.
Is Big Warm Springs crowded?
Big Warm Springs is accessible from a paved road, making it easy to reach. Weekends and holidays may be busier — consider visiting on a weekday for a quieter experience.
What should I bring to Big Warm Springs?
Essentials for Big Warm Springs: swimsuit, towel, water bottle, camping gear, a trash bag to pack out what you pack in.
Temperature
72°F
Warm Hot Boiling
Water Temp 72°F (22°C)
Avg Air Temp 54°F
Above Ambient +18°F
Mild soaking conditions March
Access
Open
Road Access Roadside
Distance to Road 238 ft
Land
Ownership State
Agency SLB
Designation SRMA
Unit State Trust Lands I-80 Block
Manager SLB
Protection 3 - Protected, subject to extractive use