A lifetime farmer in northwest Missouri, Killgore has served on the board of his distribution cooperative, United Electric Cooperative, since 1986. He has represented United on the board of NW Electric Power Cooperative Inc. since 2001. NW Electric elected him to serve on the board of Associated Electric in June 2009, and he currently serves as vice president.
Killgore and his family run Killgore Farms Inc., a 1,000-acre operation in Stewartsville, Mo., that includes row crops, cattle, and hogs. He is active in his community and church and has served on the local school board, and booster club, and currently serves on the Clinton County R-3 Educational Foundation.