This Row of 9 Mysterious Sinkholes Offers Some of the Best Swimming in New Mexico

New Mexico’s Bottomless Lakes

The 1,400-acre Bottomless Lakes State Park, established in 1933, holds the distinction of being New Mexico’s first state park. Located just outside Roswell, this unique natural wonder consists of nine cenotes (water-filled sinkholes) strung along the Pecos River valley like a necklace of blue-green gems.

If you’re ever in New Mexico, it’s one of the best places to cool off and explore the beauty of the desert.

It’s Not So Bottomless, After All

These lakes do have bottoms, ranging from 17 feet to about 90 feet deep. They formed when underground limestone caves collapsed, creating holes that filled with groundwater.

The lakes aren’t traditional but exposed parts of the groundwater table. They keep steady water levels year-round, fed by natural springs. This wee bit of rock science helped fuel the “bottomless” myth as objects would sink into this mush and seem to disappear forever.

Seven Rivers Created These Sinkholes

The lakes exist because of the Seven Rivers Formation (400 to 1,970 feet thick), a layer of rock made mostly of gypsum, dolomite, and red mudstone. This formed about 250 million years ago when an inland sea covered the area.

As the sea dried up, it left behind mineral deposits. Over time, groundwater in the underlying San Andres artesian aquifer dissolved the gypsum, creating underground caves. When these cave roofs eventually collapsed, they formed the sinkholes.

Each Lake Has Its Own “Personality”

For example, Lea Lake is the largest at 15 acres and the only lake where swimming is allowed, with a sandy beach for relaxing. Devil’s Inkwell got its name from its dark waters, caused by steep sides that block sunlight.

Figure Eight Lake looks like the number 8 from above. Fishing is permitted at Cottonwood Lake for bass, catfish, and trout. Lost Lake sometimes disappears as water levels change, and pelicans are frequently spotted near Pasture Lake during seasonal migrations.

Pecos Diamonds Form In The Gypsum Soil

Around Bottomless Lakes, you can find “Pecos Diamonds” or special quartz crystals that form in the gypsum-rich soil. When silica-rich water fills spaces in the gypsum and slowly dries out, they leave behind perfectly formed crystals. These natural gems range from clear to slightly yellow and have points at both ends.

Some specimens are as large as an inch long, though most are much smaller. You can’t collect them, but you can see an impressive display at the visitor center.

The CCC Built The Park During The Depression

The Civilian Conservation Corps (CCC) built much of what you see at the park today. From 1934 to 1940, young men from CCC Camp BR-1 worked here as part of President Roosevelt’s programs to fight the Great Depression.

They built stone picnic shelters, bathhouses, trails, and roads that are still used today. Their style focused on natural materials and handcrafting. This work provided jobs during hard times and made the lakes accessible to everyone.

Home to the Endangered Pecos Pupfish

Lea Lake is home to several endangered species, including the Pecos Pupfish, which inhabits wetlands, sinkholes, streams, springs, and the mainstem of the Pecos River.

The Rainwater Killifish, commonly found in fresh to brackish estuarine environments is another example. Such fish can transition from saline to fresh water with little stress. They’ve adapted to the saline conditions of the lakes in Bottomless Lakes State Park.

Three Trails Show Off The Park Views

Near the visitor center, Bluff Trail (less than 1.5 miles) follows the ridge above the lakes with great views of all nine sinkholes and the Pecos Valley.

The trail’s packed dirt with loose gravel so wear sturdy footwear. The super-accessible Wetlands Trail has a smooth and elevated boardwalk, a shorter 0.5-mile path through marsh areas with signs explaining the ecosystem. Mountain bikers can try the Skidmarks Trail, a moderate 3-mile loop that passes through desert scrubland.

It’s Just 12 Miles From Roswell

Located just 12 miles from Roswell, the park is easy to visit but far enough from city lights for great stargazing. The campground has 32 sites with electric and water hookups (for 26 of ’em), plus areas for primitive camping. Modern restrooms and showers make longer stays comfortable.

Many combine their trip with nearby attractions like Bitter Lake Wildlife Refuge, Roswell’s UFO Museum, or Carlsbad Caverns (about 90 minutes south).

More Things to Do at Bottomless Lakes State Park

Cool off the summer heat in Lea Lake or rent a kayak or paddleboard to explore the wildlife. The sandy shoreline is ideal for sunbathing and picnicking.

There’s a designated swim area with lifeguards on duty during the peak summer months. Fishing is popular at Cottonwood Lake and Devil’s Inkwell, which are stocked with rainbow trout in winter.

Spot herons, egrets, and various songbirds along the Wetland trail. Three wildlife viewing blinds offer a chance to spot some migratory waterfowls. If you’re a certified scuba diver, you can also explore Lea Lake’s 90-feet depth underwater.