Frank Duane Brost

Frank Duane Brost, 88, passed away on Thursday, January 1, 2026, at Ava’s House Hospice in Sioux Falls, South Dakota. A gathering to remember his life legacy will be held Saturday, January 10, 2026, at The Sanford Barn (2510 E. 54th Street North) on the campus of Sanford Health’s Research and Corporate headquarters. The family will be present starting at 1:00 pm, with the service starting at 2:00 pm. Following the service, the family invites those present to remain at the barn and enjoy refreshments and share stories.

  Frank passed away on January 1st, after living a life he may not have foreseen in his childhood on a sheep ranch in Jones County. In 88 years, Frank ventured from the banks of the White River to every state in the United States and over 40 countries around the world. Along the way, he made himself into a tremendous athlete, a successful rancher, a capable attorney, and a valued advisor and partner to elected officials, friends, family, coworkers, community members, neighbors, people on buses, folks in elevators, referees at ball games, and pretty much anyone he met. At his core, Frank wanted to help others and to be of service to the state and country he loved. He also tried to learn all he could about a world and about people he never thought he would see or meet while on the ranch he loved so much.

  Frank was born on March 8th, 1937, to Mabel Aspden Brost and Herman Brost in Alliance, Nebraska. Frank was joined by a sister, Dee, in November 1939. He was raised on the sheep ranch his parents were building along the White River south of Okaton, South Dakota.

  Frank was a four-year starter for Murdo high school, was selected for the all-state team in his senior year and eventually was inducted into the South Dakota High School Basketball Hall of Fame. He was forever proud of the Murdo Coyote team from his junior year that made it to the state tournament.

  Frank, an honor student, graduated from Murdo High School in 1955 and enrolled in the University of South Dakota Business School. He participated in basketball for two years and joined the ROTC program. Upon graduation, he received his commission as a 2nd lieutenant in Army Reserve. When he graduated in 1959, he was recognized as a Distinguished Military Graduate and went on to serve in the United States Military Reserves, retiring as a Captain in 1967.

  After a brief stint on active duty in the Army and a couple years back on the ranch, Frank enrolled in the USD School of Law in 1962. He worked for law firms in Kennebec and Sioux Falls. 

  While practicing law in Sioux Falls, Frank met and married Martha Clark in 1967. The couple moved to Presho, where Frank had purchased the practice of John Jones. Frank and Martha welcomed three boys to their family: John, Kurt and Mark. Frank was active in the Presho community beyond his law practice. He spent time on the school board, including 6 years as President, was on the South Dakota Associated School Board, served as City Attorney, sat on the local bank board, and was active in the Lions Club.

  In 1986, his friend George Mickelson asked Frank to move to Pierre and become his Chief of Staff. Frank took great pride in the work he did during this time as he worked alongside a team of talented people bringing his friend’s vision for South Dakota’s future to life. Following the death of Governor Mickelson in a tragic plane crash, Frank remained in his role at the request of Governor Walter Dale Miller as he completed George’s term.

  In 2000, Frank and Martha moved to the Black Hills. From there, he ran his ranch that he had continued to manage throughout his career and stepped up his efforts to travel the world with family and friends. In 2014, Frank and Martha moved to Sioux Falls, where they lived until his passing. During his time in Sioux Falls, Frank enjoyed watching sporting events, traveling, being a grandpa, and enjoying the many friends he had made along the way - all while continuing to make new ones.  

  Frank served his community, state, and country in many ways, but he took particular pride in his work on the State Board of Charities and Corrections, where he served as chairman. He was instrumental in the separation of those two entities during his time in state government. Later, he served on the board of the National Institute of Corrections. After 2000, he became active in the National Cattlemen’s Association, serving on the board of directors and tax committee. He was later asked to testify before Congress on behalf of the Association and the producers it represented. His passion for the business of ranching also brought him to lead the fight to repeal Amendment E in South Dakota.

  Frank was preceded in death by his parents and sister. He leaves behind his wife of 58 years, Martha; sons John, Kurt (Krista) and Mark (Elissa). He is also survived by his six grandchildren.

  If friends so desire, memorial donations may be made to the South Dakota Community Foundation, Feeding South Dakota, or the South Dakota Basketball Hall of Fame.