Big Bear Land Exchange Act (Sec. 3) This bill directs the Department of Agriculture (USDA) to convey 73 acres of identified Forest Service land to the County of San Bernardino, California, in exchange for approximately 71 acres of identified land owned by the county. Such land exchange must be for equal value. If the value of the federal land and the nonfederal land to be conveyed are not equal, the values may be equalized by a cash payment or by reducing the acreage of the federal land or the nonfederal land to be exchanged. At the option of the county, any excess value of the nonfederal lands may be considered as a gift to the United States. Any cash equalization payment that USDA receives shall be available for USDA to acquire lands, waters, and interests in land for the San Bernardino National Forest. Before completing the exchange, USDA must inspect the nonfederal lands to ensure that they meet federal standards, including for hazardous materials and land line surveys. The nonfederal lands shall be added to and managed as part of San Bernardino National Forest. Within three years of enactment of this bill, USDA must relocate the portion of the Pacific Crest National Scenic Trail that is located on the federal land to (1) adjacent National Forest System land; (2) land owned by the county, subject to county approval; (3) land within the federal land, subject to county approval; or (4) a combination of any of these.