Red Rocks

The panel's 250 million years is too old for these slopes. The Chinle beds here are Late Triassic, laid down roughly 212 to 200 million years ago by the American Museum of Natural History's reckoning, when the place was marshy floodplain. In them, a few miles north, Edwin Colbert's team opened the Coelophysis quarry in 1947. One block from that dig held a second animal unrecognized for nearly sixty years: a beaked, two-legged crocodile relative named Effigia okeeffeae in 2006, for the painter who lived beneath these cliffs.

What the plaque says

Official Scenic Historic Marker Red Rocks The colorful formations exposed here are the slope forming Chinle Shale of Triassic age deposited in streams, lakes, and floodplains some 250 mil- lion years ago and the cliff form- ing Entrada Sandstone of Jur- assic age deposited as windblown sand some 160 million years ago. These are typical landforms of the Colorado Plateau province.

Where it stands

Worth the stop nearby

• Ghost Ranch — 8.7 mi
  Red, yellow and white cliffs above the Piedra Lumbre basin, where Georgia O'Keeffe bought seven acres in 1940 and paleontologists found a hillside full of dinosaurs in 1947.
• Fuller Lodge — 25 mi
  The upright-log dining hall of a boys' ranch school, which fed and housed the Manhattan Project after the Army bought the school in 1942.
• El Santuario de Chimayó — 30 mi
  A small adobe shrine on the High Road to Taos, built around 1816 over earth that pilgrims still carry away in hope of healing.

More markers nearby

• Georgia O'Keeffe (1887-1986) — steps away
• Abiquiú — 3.7 mi
• Doña Margarita Martín — 21 mi
• Los Luceros Hacienda — 21 mi