Olin D. Sims was born September 1, 1960 in Riverton, Wyoming and raised  in the Rock Creek Valley at Mcfadden, Wyoming. He spent his entire life in agriculture, working on his family's ranch with his father Don, his brother Scott, and  their families.

Olin was known as one of the most progressive, conservation-orientated ranchers in Wyoming. The Sims family has received numerous state and national awards for their land stewardship practices. Olin planned many of the ranch's conservation projects including reservoir/wetland dam reconstruction, fencing and cross fencing pastures, developing water sources for livestock and wildlife, and adopting state-of-the-art approaches to grazing management. The ranch developed an intensive range-monitoring program to  better track changes in forage due to the ir management practices.

In 2003, the Sims family helped the Wyoming Game and Fish Department manage the irrigated hay meadows on the Wick Wildlife Habitat Management Area, located near the Sims ranch by using their livestock to execute a short duration, high intensity grazing  program designed to improve forage for wintering elk. Olin was largely responsible for launching this program, and it continues today, an example that has been followed by other land managers.

Olin served as President of the National Association of Conservation . He was instrumental in providing information to Congress that was used to develop the 2007 Farm Bill's conservation programs.

He was an avid outdoorsman and felt strongly that it is everyone's responsibility to conserve our natural resource s for generations to come. Olin passed away on December 7, 2007.