Darnell has served the Extension Service, NDSU and the public in a wide scope of responsibilities and activities since joining the staff as a specialist in agricultural engineering in 1967. He first worked with electric power and then as irrigation specialist. He was also agricultural engineering section head for two years before assuming the position of program leader for agriculture and natural resources. As irrigation specialist he became one of North Dakota*s leading authorities on water development issues and established an educational program on water quality. He served on the program leadership committee of the Extension Committee on Organization and Policy (ECOP), chaired the North Central Region agriculture and natural resources program leaders group, and has served on numerous other boards and committees at state, regional and national levels.