METCALF GAP. Metcalf Gap is a pass through the Palo Pinto Mountains in west central Palo Pinto County (at 32°43' N, 98°27' W). It was named for J. J. Metcalf, who established ranch headquarters at the pass in 1856. U.S. Highway 180 runs through the gap. The surrounding rolling hills are surfaced by clay and sandy loam that supports scrub brush, mesquite, cacti, and grasses.