Elza Hadley was a farmer, nursery man and paleontologist. He collected fossils as a teenager along the banks of Deer Creek bordering the family farm in Iowa. When he moved to Orange County, California in 1914, he gave his farm to the State of Ohio. In California he started a new collection of fossils, which he presented to the Los Angeles County Museum in 1936. His California collection numbered some 2,500 speciments, the most outstanding of which were the fishes and plants found in the miocene shales of El Modena and Alhambra. Because of his work and knowledge in the field of paleontology, he was made a member of the American Association for Advancement of Science, the Southern Califoria Academy of Sciences, the Society of Vertebrate Paleontology, and the Dana Minerological Society. He served as an Honorary Curator of Paleontology at the Los Angeles County Museum from 1936 until his death in 1951.