Lone Tree Mineral Spring

San Joaquin County County, California · Near Tracy
37.5730°N, 121.4450°W · 868 ft
73°F 868 ft Roadside

Lone Tree Mineral Spring emerges at 73°F essentially at roadside in San Joaquin County, just 1.2 feet from pavement near Tracy. This mild thermal feature represents a subtle geothermal anomaly in the rolling grassland foothill landscape, rising only 10 degrees above ambient air temperature (63°F).

Lone Tree Mineral Spring is positioned directly along the road in the Oak Ranges foothills at 868 feet elevation. The spring emerges from sandy soil in a landscape of native oak savannas and grasslands typical of the inner Coast Ranges. Water pools briefly near the road before flowing into natural drainage in an easily accessible setting.

History of Lone Tree Mineral Spring

Lone Tree Mineral Spring marks a small thermal anomaly in the San Joaquin Valley's eastern margins. The modest 10-degree elevation above ambient temperature suggests either mixing with cooler groundwater or residence time in shallow aquifers insufficient for major heating. This region sits above basement rocks associated with the Sierra Nevada batholith.

The spring is immediately accessible from the road near Tracy. No facilities exist at the location. The mild water temperature (73°F) offers minimal recreational soaking value. This site is primarily of geothermal interest as a mapped thermal feature rather than a destination spring. Visit anytime; the valley's hot, dry summers and mild winters pose no extreme access barriers."

Is Lone Tree Mineral Spring worth visiting?

Best for

  • Easy day trips
Lone Tree Mineral Spring is well suited for easy day trips.
Monthly Climate
49°
Jan
51°
Feb
54°
Mar
60°
Apr
66°
May
75°
Jun
79°
Jul
78°
Aug
74°
Sep
66°
Oct
55°
Nov
49°
Dec
Annual Precip: 15.5 in Annual Snow: 0.4 in
Best Time to Visit
December Air 49°F · Water 73°F · +25° contrast
January Air 49°F · Water 73°F · +24° contrast
February Air 51°F · Water 73°F · +22° contrast
December offers 31°F more contrast than July
What to Bring
Swimsuit & towel
Water bottle Stay hydrated, especially in hot water
Trash bag Pack out what you pack in
References
USGS Quad: LONE TREE CREEK 7.5 · NOAA: 5.0 · AMS Map: SAN JOSE
Frequently Asked Questions
What is the water temperature at Lone Tree Mineral Spring?
Lone Tree Mineral Spring has a water temperature of 73°F (23°C). This is a warm thermal spring.
Where is Lone Tree Mineral Spring located?
Lone Tree Mineral Spring is located in San Joaquin County, California at 868 feet elevation, near Tracy. Coordinates: 37.5730°N, 121.4450°W.
How do I get to Lone Tree Mineral Spring?
Lone Tree Mineral Spring has Roadside road access (4 ft from the road).
Is it safe to soak at Lone Tree Mineral Spring?
Lone Tree Mineral Spring is generally safe for soaking at its recorded temperature. Access may be on private land or unconfirmed — verify current conditions before visiting. Always tell someone your plans before visiting remote hot springs.
Is Lone Tree Mineral Spring crowded?
Lone Tree Mineral Spring 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 Lone Tree Mineral Spring?
Essentials for Lone Tree Mineral Spring: swimsuit, towel, water bottle, a trash bag to pack out what you pack in.
Temperature
73°F
Warm Hot Boiling
Water Temp 73°F (23°C)
Avg Air Temp 63°F
Above Ambient +10°F
Mild soaking conditions March
Access
Road Access Roadside
Distance to Road 4 ft