Organ Mountains

Organ Mountains

The Organ Mountains are at the southern end of the central mountain chain on the east side of the Rio Grande's rift valley. The range is nearly contiguous with the San Andres Mountains to the north and the Franklin Mountains to the south, but is very different geologically. Whereas the San Andres and Franklin Mountains are both formed from west-dipping fault blocks of mostly sedimentary rocks. The Organs are made primarily of igneous rock. The mountains take their name from the granite "needles" in the highest part of the range. Even most residents of Las Cruces do not realize that the Organs are made up of three major sections -

On the north end is a narrow ridge of vertically-jointed granite called The Needles and includes the highest point, the Organ Needle at an elevation of 8,990 feet. On the south side of the Needles is the much wider section of extrusive igneous rock, mostly a purplish-gray rhyolite. This section forms the bulk of the mountain range and reaches heights nearly as great as the needles. This section is cut in half by Soledad Canyon, which extends west from the east side of the range, separated by a low ridge and Soledad Pass from Bar Canyon on the west side. The third portion of the Organ Mountains consists of the Bishop's Cap Hills on the southwest side of the range and Rattlesnake Ridge on the southeast side of the range. This third section is much smaller and lower in elevation than the other sections of the range, and consists of fault-block limestone similar to that of the San Andres and Franklin Mountains. Established as a national monument in 2014, the Organ Mountains are one of the most rugged and beautiful mountain ranges in western United States.