By the mid-1800s, the grasslands in the valleys surrounding the San Bernardinos supported sheep and cattle ranchers, but a severe drought between 1862 and 1865 dried many lowland meadows and led ranchers to begin annual spring drives into the mountains to use food and water resources and fatten livestock for winter. Sheep belonging to Dr. Ben Barton grazed here, giving Barton Flats its name, and during the drought years his sheep grew so fat on mountain grasses that he made highland grazing a yearly practice, with the flocks wintering in Redlands and spending summers in these fertile mountain meadows through the 1870s and into the 1880s. In the late 1800s and early 1900s, cattle ranching followed a yearly cycle in which cattle wintered in the surrounding deserts and were brought each spring to the lush mountain meadows, then sold to buyers from as far as the East Coast and driven by cowboys to stockyards in Southern California or to railroads in Victorville for shipment east. The spring and fall cattle drives were major spectacles, with dust visible for miles, road traffic sometimes halted for an entire day, and calves sometimes born during the spring drives, leaving mother and calf to follow behind at their own pace. As Southern California's population grew, more people came to the mountains for recreation, solitude, and relief from desert heat, and the land became more valuable for development and recreation than for ranching, bringing the great cattle ranching days of the San Bernardinos and their cattle drives gradually to an end. Environmental concerns about logging, mining, and overgrazing led in 1893 to federal protection for most of these mountains as the San Bernardino Forest Reserve, and in 1905 the Forest Service was established and the reserve became the San Berardino National Forest. By the 1920s, increasing numbers of people came to enjoy the forest and mountain scenery, and with the development of forest roads and recreational facilities, concern grew for preserving undeveloped areas; in 1964 Congress passed the Wilderness Act, and the San Gorgonio Wilderness became one such preserved place. Native Americans came to the mountains for food, ranchers brought cattle for grass and water, and the mountains continued to offer relief from city pressures and year-round recreation, including a long tradition of youth camps that, since the early 1900s, have brought young people from across Southern California to Barton Flats, which has the largest concentration of youth camps on National Forest land in the country.