West Texas Wildlife Management
The Trans-Pecos region is the only part of Texas where mountain and desert habitats are found. This unique combination contributes to the tremendous vegetation diversity in the region, which includes at least 268 grass species and 447 species of woody plants. The vegetation diversity is also influenced by the Edwards Plateau eco-region in portions of Terrell, Pecos, and Brewster counties. In addition, there are vegetational influences in the northeast Trans Pecos by the plains ecosystem and in the southeast Trans Pecos by the Tamaulipan Province (south Texas plains). Like other ecosystems, the Trans-Pecos region is dynamic and has experienced gradual shifts in climate and vegetation. For example, there is strong paleoecological evidence that much of the Trans-Pecos region was once covered (approx. 11,000 years ago) by a mesic woodland (Van Devender 1995). However, the vegetation and wildlife has changed more rapidly in composition, abundance, and distribution over the past 120 years than at any other time in recorded history. The major influences behind these dramatic changes were (and continue to be) livestock grazing and the suppression of fire combined with frequent drought.
Considerable information about historical Trans-Pecos landscapes (prior to Anglo settlement) has been accumulated from survey records, journals, photographs, and various other records from early explorers of the region. All early accounts provide evidence that the Trans-Pecos grasslands were quite expansive and that grasslands were lightly interspersed with shrubs and desert succulents (Bartlett 1854, Parry 1857, Echols 1860, Bray 1901, Cottle 1931, Humphrey 1958, Wondzell 1984, Hall 1990). Waste-high grass was reported along Terlingua Creek and in Tornillo Flats (Echols 1860), where eroded desert exists today. Extensive grass cover was described in the Big Bend area about 1900 when high numbers of livestock were being grazed in the region (Langford and Gipson 1952). In 1885 Terlingua Creek was described as a running creek full of beaver and lined with cottonwood trees (Wauer 1973, Wuerthner 1989). Evidently, mesquite was not nearly as abundant or widespread as today, existing only as scattered shrubs among the grasslands and occurring in small isolated stands (Humphrey 1958, Johnston 1963). There is no mention of the dense stands of whitethorn acacia or catclaw mimosa that dominate some areas of the Trans Pecos today. One account in the early 1850's from the Pecos River near Horsehead Crossing noted that there were no trees or shrubs along the banks of the river (Humphrey 1958). Today, the Pecos River at Horsehead Crossing is choked with saltcedar, mesquite, and other woody plants.
By all accounts, it is evident that desert grasslands throughout the southwestern United States, including the Trans-Pecos Region, have changed since Anglo settlement. Furthermore, it is well documented that grasslands have decreased and given way to increases in woody plant abundance and bare ground in some areas (Cottle 1931, Parker and Martin 1952, Buffington and Herbel 1965, Grover and Musick 1990). Prominent invaders of the low elevation desert grasslands include creosotebush, tarbush, whitethorn acacia, honey mesquite, and cacti. Prominent invaders of the higher elevation plains grasslands include catclaw mimosa, sacahuiste, cane cholla, perennial broomweed, and prickly pear species. Numerous studies have been conducted to evaluate the causes responsible for the rapid changes in the vegetative communities. Most investigators attribute the drastic increase in shrubs to overgrazing of grasslands by livestock, and considerable evidence has been cited in support of this concept (Humphrey 1958, York and Dick-Peddie 1969, Grover and Musick 1990, Gillis 1991). Several additional factors have been hypothesized as contributing significantly to vegetation changes in semi-desert grasslands. The factors most often considered, in addition to heavy grazing, are changes in climate, suppression of grassland fires, short and long drought periods, plant competition, and erosion of topsoil in areas where vegetation has been removed. All of these factors probably have been and are contributing to a reduction in desert grasslands and an increase in shrubs.
Healthy grassland savannas exist today on certain sites where wildfires have occurred (or where prescribed fire is practiced) and on certain ranches that have been conservatively grazed and properly managed for decades. Most of these healthy grassland savannas occur at moderate to high elevations (cooler temperatures and greater average rainfall) in Hudspeth, Jeff Davis, Presidio, and Brewster counties.
Early Ranching Activity
Livestock grazing in the southwestern United States dates back to the 1500's (Humphrey 1958, Bahre 1991). In the mid-1500's cows, sheep, and horses were brought into the southwest from Mexico. Some of the animals were lost or strayed and gave rise to feral herds that grazed the region. The number of cattle, sheep, and horses increased steadily after 1598, although for many years Indian hostility forced the herders to concentrate their grazing activity near the towns of El Paso, Santa Fe, Taos, and Tucson (Humphrey 1958). Spanish missionaries and farmers gradually increased the number of sheep and goats along the Rio Grande between El Paso and present day Presidio, herding sheep into the Trans-Pecos high country during the summer (Carlson 1982). The number of sheep and goats gradually declined after 1767, when the Spanish decided to retreat from most of Texas and New Mexico. In the Big Bend region, Milton Faver was reportedly the first Anglo rancher, who moved into southern Presidio County in 1857. He subsequently built a sizeable cattle herd (10,000-20,000 head), along with 5,000 sheep and 2,000 goats
Extensive ranching in the Trans-Pecos began in the early 1880's when the first Anglo Americans settled in the Big Bend region. Livestock numbers peaked in the late 1880's soon after completion of the Texas and Pacific Railroad (in 1883) through the region. By 1885 relatively large herds of livestock were being raised in the Trans-Pecos. But it was not long before drought and severe winters (1885-1895) drastically reduced the herds. By 1905 many of the cattle companies operating in 1885 were out of business. Range conservation and management was born subsequent to the "appalling" losses of cattle from drought and starvation, the lowered rangeland productivity, and "the associated evils of soil erosion, water loss, and encroachment by noxious weeds" (Gould 1951).
Given the descriptions of the vegetation by early explorers, it is not difficult to understand what attracted these early ranchers to the Trans-Pecos region. For example, Juan Mendoza in 1864 (in present day Presidio County) describes "a beautiful plain, with plentiful pasturage of couch grass." Captain John Pope in 1854 described the Trans-Pecos area as " . . .destitute of wood and water, except at particular points, but covered with a luxuriant growth of the richest and most nutritious grasses known to this continent. . . The gramma-grass, which exists in the most profuse abundance over the entire surface of these table-lands is nutritious during the whole year, and . . . seem intended by nature for the maintenance of countless herds of cattle” (Weniger 1984). What the early ranchers could not have understood is the complexity of interacting factors that allowed this sensitive ecosystem to support the vast expanses of grasslands and grassland-savannas. The first settlers were probably unaware of the brutal droughts that frequently occur in this region. They probably did not comprehend the critical role of periodic natural fires in maintaining the health and integrity of the grassland systems. Finally, a concept they could not have understood is that an ecosystem maintained by frequent drought, periodic fire, and very low numbers of grazing animals is not capable of supporting high numbers of grazing animals on a continuous or long-term basis without rangeland degradation.
To provide some idea of the livestock densities that were grazed in the region, some specific examples are described below (present day stocking recommendations normally range from 75 to 200+ acres/animal unit ):
In 1881 the Iron Mountain Ranch near Marathon was stocked with 27,000 head of sheep on 45,000 acres, a stocking rate of 8.3 acres/animal unit (Clayton 1993).
In the mid-1880's, Lawrence Haley was running 15,000 sheep on 37,000 acres south of Alpine, a stocking rate of 12.3 acres/animal unit (Carlson 1982).
In the mid-1890's, the Downie Ranch in Pecos County was stocked with 20,000 head of cattle, 80,000 sheep, 2,000 goats, 500 horses on 234 sections, a stocking rate of 4.1 acres/animal unit (Downie 1978).
In the mid-1890's, the Western Union Beef Company stocked 400 sections near Fort Stockton with 30,000 head of cattle (8.5 acres/animal unit), but only 22,000 head (11.6 acres/animal unit) could be found in 1897 after the Indians, rustlers, and predators had their share (Downie 1978).
The high stock densities during the 1880's and 1890's certainly had an impact on vegetation and on rangeland productivity, including soil erosion-- as was indicated by descriptions of drought and starving animals. However, high stocking rates in many areas of the Trans Pecos during the next 4 or 5 decades continued to deteriorate rangelands and permanently reduce rangeland productivity. Sheep and goat numbers in the Trans Pecos gradually increased during the early 20th century and peaked in the 1940's. The sheep and goat industries in West Texas remained strong through the 1950's and 1960's and then steadily declined.