Willowcroft Manor was listed in the Colorado State Register in March 1993. The six buildings comprising the property were nominated under for their association with Joseph W. Bowles, a prominent rancher and politician who served two terms in the state legislature, as well as significance in the areas of agriculture, architecture, and exploration/settlement. The 1884 Willowcroft Manor was one of the earliest and largest ranches in the South Platte River Valley.