Prehistoric Clovis culture peoples[4] in Reeves County lived in the rock shelters and caves nestled near water supplies.

In 1849, John Salmon "RIP" Ford[10] explored the area between San Antonio and El Paso, noting in his mapped report the productive land upon which the Mescalero Indians farmed.

Pecos Army Air Field was one of the 120 airbases that trained the pioneer Women Airforce Service Pilots[20] to fly military aircraft.

At the Pecos installation, WASP flew AT-6, UC-78, and AT-17 aircraft in engineering tests, administrative duties, and transporting freight.

Pecos is the site of the largest private prison in the world, the Reeves County Detention Complex, operated by the GEO Group.

[22] According to the U.S. Census Bureau, the county has a total area of 2,642 square miles (6,840 km2), of which 6.7 sq mi (17 km2) (0.3%) are covered by water.

In 2020, Donald Trump not only flipped Reeves County, but won the greatest margin of victory for a Republican presidential candidate since President Nixon's 1972 re-election at 61.1%.