Science

Ecology Overview

Tombstone Courthouse State Historic Park is located in the city of Tombstone in Cochise County in southeastern Arizona and has been operating as a State Park since 1959. Tombstone is located in the Upper San Pedro Basin. The Upper San Pedro Basin lies within the Chihuahuan and Sonoran Deserts. Average annual precipitation in the Upper San Pedro Basin varies from about 10 to 12 inches along the San Pedro River up to greater than 30 inches in Huachuca Mountains. The climate of the Upper San Pedro Basin is arid to semi-arid with average temperature maximum in the low to mid 80° F and average low of mid 40° F. Elevation at Tombstone is 4539 feet.

Tombstone is located within a short driving distance from the San Pedro Riparian National Conservation Area (SPRNCA). The SPRNCA contains an estimated 40 miles of the upper San Pedro River and designated by Congress as a National Conservation Area in 1988. A significant feature of the area is its diversity of plant life. Representative Chihuahuan desert-scrub upland  species include Tarbush, Creosote and Acacia. The riparian deciduous broadleaf woodland community is associated with the San Pedro River and its springs and tributaries. Representative tree species include Fremont’s Cottonwood, Willow, Mesquite, and Arizona Ash and Walnut.

The SPRNCA has a great diversity of wildlife species stemming from the riparian habitats, associated perennial water sources, grass dominated bottomland and Chihuahan desert-scrub upland habitats. It is home to more than 80 species of mammals, over 40 species of reptiles and amphibians, 2 native fish species (longfin dace and desert sucker), over 150 species of breeding birds and more than 250 species of migrant and wintering birds. Mammals include several bat species such as the Mexican free-tailed bat and the Big brown bat. Other commonly observed mammal species include mule deer, javelina, mountain lion and bobcats. Bird species of interest include the green kingfisher, yellow-billed cuckoo, the Gray Hawk, and Mississippi Kite.

Native habitats, endangered species and plant community composition and diversity are impacted by the occurrence of less desirable non-native (also known as invasive) plant and animal species in Arizona.  Problem non-native invasive species, due to their potential to invade an area and cause adverse ecological impacts found within SPRNCA Saltcedar, Johnson’s , Bermuda and rabbit-foot grass, bullfrogs, mosquitofish, and common carp, yellow bullhead.