Rather than being a single coherent range, the Davis Mountains are an irregular jumble of isolated peaks and ridges separated by flatter areas. The mountains occupy a rough square about on each side. The mountains are of volcanic origin composed of strata associated with eruptions of the Trans-Pecos Texas volcanic field 35 million years ago. The highest peak in the Davis Mountains is Mount Livermore at the fifth-highest peak in Texas.
Vegetation
The Davis Mountains are a sky island, an isolated mountain range surrounded by desert. The town of Fort Davis at the foot of the Davis Mountains has an elevation of. From that elevation, the sky island rises to. As the elevation increases, average temperatures decline and precipitation increases, permitting an "island" of forest and other mesic habitat at higher elevations. The most common vegetation of the Davis Mountains is montane grassland, often mixed with scattered bushes and trees. As is common in most Northern Hemisphere semiarid climates the vegetation on the southern slopes of the mountains is noticeably sparser than on the northern slopes. This is due to the greater exposure to the sun on southern slopes, thus warmer temperatures and drier soils. Mixed in with the grassland, and usually at higher elevations, are four woodland and forest zones. First, at elevations below and at higher, drier elevations, the dominate tree species is the alligator juniper mixed with oak species and pinyon pine. Secondly, woodlands with pinyon pine as the most common species are found on steep slopes at elevations of. Third, woodlands in which the gray oak is the most common tree and mixed with other oak species are also found on steep slopes at elevations of. The gray oak woodlands are found in slightly moister soils than the pinyon woodlands. The richest and most diverse of the woodlands and forests in the Davis Mountains are the mesic forests found from. These forests are found in stream valleys and other well-watered areas. Indicator species are ponderosa pine and southwestern white pine, plus two small groves of quaking aspen at elevations of at the base of the cliffs surrounding the summit of Mount Livermore. Aspens are more characteristic of the higher elevations in the Rocky Mountains. The mesic woodlands are remnants of past glacial ages in which the climate of West Texas was more humid and cooler than at present.
Fauna
Over 277 species of birds have been seen at Davis Mountains State Park. Many species found here are characteristic of more northerly mountain climes or alternatively of nearby Mexico, including 10 species of hummingbirds. Large mammals found here include whitetail deer, mule deer, elk, black bear, cougar, pronghorn, peccary, and introduced species such as aoudad and feral hogs. Several private ranches in the Davis Mountains offer hunting opportunities.
Climate
Nearly all of the Davis Mountains fall into the climate classification of BS in the Köppen climate classification system. However, the highest elevations may transition into a cooler, wetter Cfb climate.
Conservation
Most of the Davis Mountains are in private ownerships. However, since 1996, the Nature Conservancy has acquired 33,000 acres in the Davis Mountains range, along with conservation easements on 70,000 adjoining acres of private ranchland. The Davis Mountain Preserve is open to the public at specified times.
Facilities
is accessed by Spur 78 from State Highway 118. Spur 78 is the highest state maintained road in Texas at 6,791 feet near the summit of Mt. Locke where the older telescopes of the observatory are located. Spur 77 branches off from Spur 78 providing access to the newer research equipment atop Mt. Fowlkes.
Texas separatist standoff
The Texasseparatist organization known as the Republic of Texas has its origins in the Davis Mountains. On April 27, 1996, the leader of the group, Rick McLaren, staged an attack on his neighbor's house and demanded that he cede his property to the Republic of Texas. This led to 300 state troopers surrounding his house with his five followers, his wife, the victims of the attack, and him inside for close to a week. Ultimately, one follower was shot in the standoff and McLaren was arrested and imprisoned for the equivalent of a life sentence.