He served as the head football coach at the University of Utah from 1910 to 1913 and at the Agricultural College of the State of Montana—now Montana State University—from 1914 to 1917, compiling a career college football record of 27–15–8.

Bennion was also the head basketball coach at Brigham Young University (BYU) from 1908 to 1910, at Utah from 1911 to 1914, and at Montana Agricultural from 1914 to 1919, amassing a career college basketball record of 96–31.

In addition, He was the head baseball coach at BYU from 1909 to 1912, tallying a mark of 11–10.

Following his coaching career, he worked as an agricultural agent in Umatilla County, Oregon and Montana during the 1920s.

From 1946 to 1955, Bennion served as the executive director of the Colorado Pueblo Expenditures Council in Denver.