What we know today as the park’s approximately 3,828 acres are made up of parcels of land acquired over the years. The properties that make up the park are rich in human history, having supported a variety of uses, including:

• Homesteading and a family retreat in the middle of the park site
• Ranching on the southern portions of the site
• Logging and a turn-of-the-20th-century sawmill in the northern part of the site
• A sportsman's club on the western side of the site

The first 1,720-acre parcel was donated to Colorado Parks and Wildlife in 1986 by Frances Hornbrook Staunton, daughter of Drs. Rachel and Archibald Staunton, who homesteaded the land beginning around the turn of the 20th century.

Subsequent parcels, including a portion of the Davis Ranch and Elk Falls property, were acquired in the late 1990s.

In 2006, a small key parcel, called the Chase property, was added to the park to reach its current land base of approximately 3,828 acres. This parcel was once owned by Mary Coyle Chase, a Denver native, journalist and playwright best known for her play Harvey, which won the Pulitzer Prize for drama in 1945.

In November 2014, former Colorado State Senator and Representative Allen Dines donated 80 acres and his family vacation home to Colorado Parks and Wildlife. It was the last private property surrounded by the park. This acquisition allowed for rerouting of the Staunton Ranch trail and an area for hike-in tent campsites. It remains a corridor for wildlife migration through the park.