San Gregorio Reservoir, a small irrigation reservoir pre-dating the wilderness designation, is the largest body of water in the San Pedro Parks Wilderness. Several small streams that wander through the forest openings support strong trout populations, including the Rio Grande cutthroat trout. A large herd of elk summers in the wilderness.

The Santa Fe National Forest is 1.6 million acres of mountains, valleys and mesas ranging from 5,000 to 13,000 feet in elevation. Visitors find forested mountains slopes, colorful volcanic formations, deep river gorges and primitive wilderness. Thousands of cultural and archaeological sites reflect the Santa Fe National Forest's rich historical heritage and the many cultures that value this landscape.

The Santa Fe National Forest has a number of special places, including wilderness areas, wild and scenic rivers, a national recreation area and scenic byways.

There are four wilderness areas on the forest. They cover almost 300,000 acres. Wilderness areas provide primitive recreation options. 

The Wild and Scenic Rivers Act was passed by Congress in 1968 to protect outstanding free-flowing rivers.There are three wild and scenic rivers on the Forest: the Rio Chama, Pecos, and East Fork of the Jemez. 

National recreation areas (NRAs) were established by Congress to preserve enhanced recreational opportunities in places with significant natural and scenic resources. NRAs emphasize a variety of activities for visitors, including hiking, camping, boating, fishing, swimming, biking, horseback riding, and wildlife viewing, in areas that include multiple-use management focused on conservation and limited utilization of natural resources. The Jemez National Recreation Area (JNRA), the only NRA in the Forest Service Southwestern Region, was designated by Congress in 1993 to conserve its recreational, natural and cultural resources. 

The National Scenic Byways Program is a collaborative effort administered by the Federal Highway Administration that recognizes special roadways for their outstanding and unique historic, cultural, natural, archaeological, recreational and scenic qualities. The Santa Fe National Forest has two Scenic and Historic Byways.

Vacas Trail
At the San Gregorio Lake Trailhead is a 10-15 car parking lot with a toilet. The elevation here is 9,300 feet. The climb into the San Pedro Parks Wilderness is gradual. San Gregorio Reservoir is about a mile from the trailhead. From the reservoir to trail #50 (Palomas) terminus is approximately 4 miles. The trail then crosses the terminus of Trai l#435 (Anastacio) in about a quarter of a mile. The trail then proceeds to the terminus of trail #32 (Penas Negras) in about 2.5 miles, and from there San Pedro Park is about a half mile. The trail passes mostly through spruce-type vegetation with occasional openings. Water is abundant along the trail.