Soda Dam

What to expect

Soda Dam is a lump of pale, knobbly rock that sits across the Jemez River in the canyon north of Jemez Springs, in the Santa Fe National Forest. It looks like a small version of the terraces at Yellowstone’s Mammoth Hot Springs, which is how the Jemez Valley Historical Society describes it. The rock is travertine, a form of calcium carbonate laid down by mineral springs that rise along the Jemez fault zone.

About fifteen springs and seeps feed the formation. Their water is heated at depth by the volcanic system under the Valles Caldera, picks up dissolved minerals as it moves through limestone and shale, and drops them as it reaches the surface and cools. Over thousands of years that crust grew into a dam across the river. The Jemez River now pours through a gap in it, and the water foams and churns as it drops into a pool at the base.

Be clear about what this place is. Soda Dam is not a soaking hot spring. The springs that built it come out as small warm trickles and seeps. The historical society puts the seeps along the highway at about 80°F27°C or warmer, and Wikipedia gives a maximum source temperature of about 117°F47°C. You will see orange, green and yellow streaks of algae and minerals where the water runs, and you will smell it. But there is no pool of spring water big enough to sit in.

What people do here is look, take photos, scramble around the edges of the formation and, in summer, swim or wade in the river pool below the falls. That pool is mostly river water. It can be refreshing on a hot August afternoon and painfully cold in May.

The history in the rock

The formation once blocked the canyon more completely than it does now. According to the Jemez Valley Historical Society, the dam stood across the valley until the road was blasted through it in the 1960s. When crews built NM 4, the blasting changed the underground plumbing. Much of the spring flow now drains into ditches on either side of the highway, and some springs stopped flowing altogether. The part of the dam left standing lies on the east side of the road.

People used this spot long before that. Jemez Cave, close to Soda Dam, holds artifacts that show human use going back to about 2,500 B.C., and finds from the 1930s point to several cultures using the area over more than 2,000 years. The Forest Service took over management of Soda Dam in 1976. Jemez Cave itself is closed to the public under Forest Service order 03-10-03-25-04 to protect its natural and cultural resources, so do not go looking for it.

Getting there

From Albuquerque, take US 550 northwest to San Ysidro and turn north onto NM 4. Follow it through Jemez Pueblo and up the red rock canyon into the village of Jemez Springs. Keep going north past the Jemez Ranger District office. Soda Dam is on the right, roughly 2 miles beyond the village, where the road squeezes through a cut in the rock. There are pullouts close by. From Los Alamos, take NM 4 over the mountains past La Cueva and Battleship Rock and continue south.

The highway is paved all the way. The formation is a couple of minutes on foot from the pullouts. A short, informal loop wanders around it, but the rock is uneven and wet in places, so there is no wheelchair-friendly path to the river.

When to go

Soda Dam is worth a stop at any time of year, since the main draw is the formation itself.

• Late summer and early fall are best if you want to get in the water. The river is usually lower and warmer by then.
• Spring runoff, roughly April to June in a normal year, makes the river high, fast and cold below the falls. Look, do not swim.
• Winter can bring ice on the rock and on NM 4. The approach from San Ysidro is usually the easier drive.

Summer weekends are busy because Soda Dam sits on the main road between Albuquerque and the Jemez high country. Early mornings are quieter.

The 2026 McCauley Springs Fire closed several sites farther up NM 4 but not Soda Dam, and no current closure covers it.

Rules and etiquette

Soda Dam is on Santa Fe National Forest land, so forest-wide rules apply:

• Swimsuits required. Occupancy and use order 10-494 bans public nudity on all Santa Fe NF land, roads and trails. It also bans alcohol for anyone under 21. It runs until Dec 31, 2026 unless rescinded; check for a renewal.
• No camping at the site. Local visitor guides list the primitive springs in this canyon as day use only, sunrise to sunset.
• No fires and no littering.
• Stay off the fragile parts of the formation. Travertine breaks easily, and once it is gone it takes centuries to rebuild. Do not chip off samples, carve the rock or pile it into dams.
• Do not drive onto the formation. Park in the pullouts.

There is no fee to stop.

Where to stay nearby

• Jemez Springs, just south, has small inns, cafes and two paid soaks with real hot water: Jemez Hot Springs, with outdoor pools by the river, and the historic Jemez Springs Bath House.
• Jemez Falls Campground, off NM 4 north of Battleship Rock, is a seasonal Forest Service campground (usually May to November).
• Redondo Campground, farther up NM 4, is another Forest Service option in season.
• San Antonio Campground, on NM 126 near La Cueva, is the base for San Antonio Hot Springs.

The Jemez Ranger District office, just south of Soda Dam, can tell you which campgrounds are open.

Safety notes

• Moving water: the current through the gap and below the falls is strong, especially in spring. Do not jump in without checking depth and flow.
• Slippery rock: wet travertine is slick and sharp. Wear water shoes.
• Traffic: NM 4 is narrow here. Watch children near the road and cross carefully.
• Warm water: keep your head out of any warm pool or seep, since warm springs can carry the amoeba Naegleria fowleri.
• Do not drink the spring or river water.

Nearby stops worth adding

Spence Hot Spring, about 5 miles north on NM 4, is the closest place to actually soak, a short walk from a small paved lot. McCauley Warm Springs is a 2-mile hike from Battleship Rock. Back in the village, Jemez Historic Site protects the ruins of Giusewa Pueblo and its Spanish mission church.