Eggenhofer was born in Gauting, Bavaria on December 5, 1897.
"[3][4] Eggenhofer became a painter in the late 1950s, and he moved his studio to Cody, Wyoming in 1961.
[6] He exhibited his work at the Buffalo Bill Center of the West in Cody, Wyoming in 1975 and 1981, and at the Museum of Western Art in Kerrville, Texas in January 1985.
[5] He was a member of the Cowboy Artists of America from 1970 to 1974, and he won the Trustees Gold Medal from the National Cowboy & Western Heritage Museum in Oklahoma City, Oklahoma in 1973.
[4] Eggenhofer died on March 7, 1985, in Cody, Wyoming, at age 87.