Conrad Kohrs Warren [1907-1993], grandson of Conrad Kohrs, took over management of what remained of the cattle empire in 1932. It is thought he specifically purchased the ranch house contents from Kohrs Family Trust in 1940 to prevent dispersal at the time of the elderly Augusta’s passing. A progressive rancher, Warren raised prize-winning Hereford cattle and Belgian draft horses. He was president of the Montana Stock Growers Association, and was on the state sanitary commission and county high school board. Warren was a staunch advocate for Montana Indian ranchers. He was instrumental in establishing the state's public livestock auction system to protect ranchers from unscrupulous buyers.

Nellie Flinn Warren [1911-1979] moved to Deer Lodge when her father became conductor for the Milwaukee Railroad. Like her grandmother-in-law Augusta, she considered her proper sphere to be the home. Nellie was a devoted mother who encouraged her children, Patricia and Conrad, to explore their own interests. Later they remembered, "We never learned anything in school that we hadn't already discussed around the kitchen table."

The Warrens began to explore ways to preserve their heritage when their children left to pursue other careers. Con struggled to preserve the ranch through changing times. Nell worked to document its history. She encouraged her husband to make the ranch a museum. Their efforts succeeded in 1972 when the ranch became a National Historic Site within the National Park System.