MCKINNEY MOUNTAIN. McKinney Mountain is thirty-six miles southwest of Alpine in west central Brewster County (at 29°50' N, 103°47' W). Its summit, at an elevation of 5,006 feet above sea level, rises 1,225 feet above the O2 Ranch, two miles northeast. The soils on the mountain are shallow and stony; local vegetation includes live oak, piñon pine, juniper, and grasses. The peak is named for W. Q. McKinney, who in 1886 built a rock house at the site of the future O2 Ranch.