Orthello L. “Willy” Wallis was born May 1, 1921. He served as a ranger naturalist at Crater Lake National Park in 1946 and 1947 and as a Naturalist in Yosemite from 1950 to 1954. He then transferred to Lake Mead National Recreation Area. Wallis eventually became Chief Aquatic Science for the Park Service. He retired and starting in 1984 worked as a volunteer at Tuolumne Meadows during the summer for at least 4 years. Wallis resides in San Rafael, California. According to Shirley Sargent in Protecting Paradise (1998) he was

Sometimes called “Mr. Fish” because of his intense interest in the history and management of trout, Wallis was an outstanding man and wrote well. Not only was he on active duty with the Marines in WW II but was wounded on Okinawa. After the war he obtained his Masters degree in fish and game management before returning to Yosemite. . . . His research and writing of a comprehensive manuscript entitled “Yosemite Trout Investigation, 1951-1953,” is held in the Yosemite Research Library.

• Fishes of Yosemite National Park (1941, 1948) by Willis A. Evans and Orthello L. Wallis

• Wallis, OL, The Status of the Fish Fauna of the Lake Mead National Recreational Area, Arizona-Nevada, Transactions of the American Fisheries Society

• Wallis, Orthello L., Research and interpretation of marine areas of the U.S. National Park Service United States. National Park Service. 1958

• Wallis, O. L. 1947. A study of the mammals of Crater Lake National Park. M.S. Thesis. Oregon State Coll., Corvallis.

• Wallis, OL, Yosemite's Pioneer Arboretum, Yosemite Nature Notes

• Wallis, OL, Trout studies and a stream survey of Crater Lake National Park, Unpublished MS Thesis. Oregon State University, 1948

Fishes of Yosemite National Park by Willis A. Evans and Orthello L. Wallis