In In 1839 Governor Juan Alvarado granted the 13,000-acre tract called Cucamonga to Tiburcio Tapia, an ex-soldier who was a prominent merchant and alcalde in Los Angeles. A half-mile west of this marker Tapia, employing Indian laborers, immediately built an adobe house on a vantage point on Red Hill. The large adobe was abandoned in 1858 when Tapia's heirs sold the rancho. The adobe soon disintegrated into its native earth. This marker is located on land which once was a part of Tapia's rancho.

Citation from California Office of Historic Preservation