Doña Ana Mountains
The Doña Ana Mountains are a mountain range in Doña Ana County, New Mexico. The highest elevation in the range is Doña Ana Peak at , at . Description The Doña Ana Mountains are a small, rugged mountain range in the desert a few kilometers north of the city of Las Cruces, New Mexico and just east of the Rio Grande. The range is bounded by escarpments to the east and south. Doña Ana Peak is located in the southeastern part of the range, where it is prominent viewed from Las Cruces, and Summerford Mountain is prominent in the northeast corner of the range. The range is heavily eroded and largely barren of vegetation, exposing some of bedrock. Geology The mountains were formed in the late Tertiary as a fault block, which was uplifted on the east side along the Jornada fault and subsided to the west along the Robledo fault. This tilted the block by about 15 degrees towards the west. The northern part of the mountains is underlain by Pennsylvanian and Permian sedimentary rock, with a large syenite sill at Summerford Mountain. The middle section is Eocene lava flows and volcaniclastics (broken volcanic debris) of the Palm Park