File:Sandoval County, NM, USA - panoramio (2).jpg — cc by-sa 3.0
San Antonio Warm Spring flows at 101°F (38.5°C per USGS) within the Valles Caldera National Preserve at 8,431 feet. The water is 56°F above local ambient, mildly acidic at pH 6.7, and low in dissolved minerals. Managed by the National Park Service, the spring has roadside access just 44 meters from the road.
The spring surfaces inside the Valles Caldera, a massive volcanic depression in the Jemez Mountains of northern New Mexico. At 8,431 feet, the caldera floor supports expansive mountain meadows ringed by mixed-conifer forest. The area receives 23 inches of rain and 53 inches of snow annually, creating a lush landscape sharply different from the surrounding desert lowlands. The East Fork of the Jemez River and several tributaries drain the caldera, and elk herds are a common sight across the grasslands.
History of San Antonio Warm Spring
The Valles Caldera formed roughly 1.25 million years ago in a catastrophic eruption. San Antonio Warm Spring draws its heat from the residual magmatic system beneath the caldera floor. The preserve was a private ranch (Baca Ranch) for over a century before Congress acquired it in 2000. The National Park Service assumed management in 2015. The spring carries permanent protection status with open public access, subject to preserve regulations and seasonal closures.
Check Valles Caldera National Preserve operating hours and seasonal road closures before visiting; the preserve gate controls entry and winter access is limited. At 8,431 feet, afternoon thunderstorms are common in July and August, and temperatures drop sharply after sunset even in summer. San Antonio Campground, 12 km south in the Santa Fe National Forest, is the nearest reservable camping option and operates May through October.
Is San Antonio Warm Spring worth visiting?
Best for
- Hot spring soaking
- Easy day trips
- Overnight camping trips
San Antonio Warm Spring offers an accessible hot spring experience — great for a day trip.
Annual Precip: 22.9 in
Annual Snow: 53.0 in
January
Air 25°F · Water 101°F · +77° contrast
December
Air 25°F · Water 101°F · +76° contrast
February
Air 27°F · Water 101°F · +74° contrast
January offers 41°F more contrast than July
Recent Temperature
101.3°F
(38.5°C)
Measured Aug 01, 1947
The water at San Antonio Warm Spring is slightly acidic (pH 6.7).
pH influences mineral absorption through skin
May support bone density and joint health
Known for muscle relaxation and stress relief
Traditionally used for skin conditions and inflammation
Natural antiseptic with skin health benefits
Overview
San Antonio Campground is adjacent to the San Antonio River, tucked into a forest of ponderosa pine at 7,600 feet above sea level. This popular campground is open from May through October in the Santa Fe National Forest. Visitors should be prepared for hot summer days and cool nights.
San Antonio Campground was completely rebuilt and reopened in August 2010. It is designated as a reduced impact and recycle campground.Recreation
A paved walking trail along the river provides access f...
Reserve on Recreation.gov →
Swimsuit & towel
Water bottle
Stay hydrated, especially in hot water
Warm layers
Cold air before and after soaking
Camping gear
Nearby camping at San Antonio Campground
Trash bag
Pack out what you pack in
5 miles from Santa Teresa, NM
USGS Quad: VALLE SAN ANTONIO 7.5 · PP 492: 11.0 · NOAA: 1.0 · AMS Map: ALBUQUERQUE
What is the water temperature at San Antonio Warm Spring?
San Antonio Warm Spring has a water temperature of 101°F (38°C). This is considered a hot spring, well above body temperature.
Where is San Antonio Warm Spring located?
San Antonio Warm Spring is located in Rio Arriba County, New Mexico at 8,431 feet elevation, near Santa Teresa. Coordinates: 35.9720°N, 106.5600°W.
How do I get to San Antonio Warm Spring?
San Antonio Warm Spring has Roadside road access (144 ft from the road).
Is San Antonio Warm Spring free to visit?
San Antonio Warm Spring has Open access. It is managed by National Park Service.
Can I camp near San Antonio Warm Spring?
Yes, San Antonio Campground is located nearby (7.6 miles away).
What minerals are in the water at San Antonio Warm Spring?
Water chemistry analysis shows the presence of pH, Calcium, Magnesium, Sulfate, Chloride. The pH is 6.7 (slightly acidic).
Is it safe to soak at San Antonio Warm Spring?
San Antonio Warm Spring is generally safe for soaking at its recorded temperature. Always tell someone your plans before visiting remote hot springs.
Is San Antonio Warm Spring crowded?
San Antonio Warm 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 San Antonio Warm Spring?
Essentials for San Antonio Warm Spring: swimsuit, towel, water bottle, warm layers for before and after soaking, camping gear, a trash bag to pack out what you pack in.