Clayton Lake State Park, State park and dark sky observation site in Union County, New Mexico.

Clayton Lake State Park is a 170-acre reservoir in rolling grasslands and sandstone bluffs at the western edge of the Great Plains, 15 miles north of Clayton. The lake was created in 1955 by damming Seneca Creek; a 28-meter dam holds back 300,000 cubic meters of water. A 0.25-mile trail leads to the dam spillway, where over 500 dinosaur tracks are exposed in Dakota Group rock.

Clayton Lake was created in 1955 by damming Seneca Creek as a fishing lake and winter waterfowl resting area. The State Game and Fish Commission declared the lake area a recreation site that year, and it became an official state park in 1967. In 1982 a flood washed away the topsoil of the 46-metre-wide spillway, exposing a Dakota Group rock layer with about 500 dinosaur tracks.

The observatory here lets visitors study constellations and celestial bodies in one of the darkest locations in New Mexico. Programs are designed so people can observe the night sky without light pollution interfering with their view.

The park offers 26 developed campsites with electrical hookups, modern restrooms, and showers for overnight stays and day visits. The facilities and gentle terrain make the area accessible for most visitors.

The exposed bedrock near the spillway shows over 500 fossilized dinosaur footprints from the Cretaceous period. These tracks remain visible to visitors walking along the site and tell the story of ancient life in this area.