Rocky Butte is a prominent volcanic landscape feature on the northeast side of Portland, Oregon, and includes the Grotto, a property owned by the Roman Catholic Church at the location of a former quarry by the Union Pacific Railroad from the late 1800's until it was purchased by Father Ambrose Mayer in 1923. In 1935 the crest of Rocky Butte was given to Multnomah County by Joseph A. and B.W. Hill. "Joseph Wood Hill Park" was created at the summit and dedicated to the public in memory of their father, Dr. J.W. Hill.