The Rio Grande Gorge is a geological feature in northern New Mexico where the watercourse of the Rio Grande follows an eroded chasm. Beginning near the Colorado border, the approximately 50-mile gorge runs from northwest to southwest of Taos, New Mexico, through the basalt flows of the Taos Plateau volcanic field. The gorge depth is 800 feet j…The Rio Grande Gorge is a geological feature in northern New Mexico where the watercourse of the Rio Grande follows an eroded chasm. Beginning near the Colorado border, the approximately 50-mile gorge runs from northwest to southwest of Taos, New Mexico, through the basalt flows of the Taos Plateau volcanic field. The gorge depth is 800 feet just south of the Rio Grande Gorge Bridge, which spans the gorge 10 miles northwest of Taos.