OverviewThe Robledo Mountains of southern New Mexico are a small range just north of Las Cruces. They line the Rio Grande River on the west bank as the river winds its way south near the town of Radium Springs. The range includes an incredibly diverse landscape including juniper dotted volcanic mountains, dramatic limestone, igneous and volcanic cliffs, remote grass-covered hills, mesas, and buttes, caves, deep and rugged 'box' canyons with riparian habitats, expansive desert grassland swales, and creosote-dominated lowlands.
Robledo TrackwayThe Robledo Mountains contain high limestone peaks, deep canyons, sprawling caves, streams, and significant prehistoric archeological sites. The perfectly preserved Permian period Pelycosaur vertebrate Trackway (a line of tracks)- 280 million years old is among the oldest finds in the world and one of the most significant discoveries in North America.
Trackway excavated from the Robledo find are on display at the Natural History Museum at the Smithsonian Institute, the Carnegie Museum of Natural History and the Natural History Museum of Los Angeles County.
600 million years ago, Southern New Mexico was covered by a great inland sea. When the sea retreated, it left behind many fossils. Las Cruces teemed with reptiles and amphibians, whose stories are told in the abundant scattering of fossils in the Robledo Hills. Fossils found here are remarkable - containing the most abundant and diverse assemblage of terrestrial trace fossils in the world.
The monumental Trackway find can be attributed to the perseverance of one man, JERRY MACDONALD, who as a geology student at NMSU made the discovery and spent 8 years of his life dedicated to the excavation & research of the creatures that lived along the tropical shores of the great Southwest Ocean 50 million years before dinosaurs roamed the land. These early reptiles preceded the Triassic period (early mammals) and the Jurassic period (age of dinosaurs).