In Irvington he participated in a search for elephant and horse remains with Charles Allen and Emery Munyan which were discovered by them between 1867 and 1876. Prior to it, he also discovered a tusk and a jaw of a mastodon in 1871 in Mission San Jose, which was measured to be 24 inches and was the most complete jaw ever discovered in the state of California. He sent the jaw to Yale College for examination and collected more elephant fossils which he found 40 feet (12 m) below the surface in 1872 which were examined at the Wabash College.