1891 - The Crow Indian tribe cedes 1.8 million acres from the western end of their reservation. This cession includes the Dryhead country, which open the area to prospecting and homesteading.
1900 - The ranch site is settled by Lincoln Hannon, his wife Alice, and their two children. Hannon builds several structures, including a small log cabin and irrigates 20 acres of hayfields. The family inhabits the site for 5 years before moving to British Columbia.
1905 - The property is purchased by George W. Burkey. Very little is known about the four years Burkey owned the ranch site. He did become postmaster for the area until it was closed in 1908.
1909 - James Wasson of Kane, Wyoming, files a homestead claim on the land that will later become the L/Heart Ranch.
1909-1926 - Wasson makes $2,000 worth of improvements to his 160 acre claim. These includes a log house, two chicken houses, a spring house, tool house, bunkhouse, root cellar. He also cultivates 20 acres of alfalfa and builds fencing.
1925 - Caroline Lockhart, Lou Ketchum, and Lou Erickson file individual 640-acre homestead claims on land adjoining the Wasson place.
1926 - Lou Erickson purchases the 160 acre Wasson Place.
1926 - Lockhart purchases the 160 acre Wasson Place from Lou Erickson and establishes L/Heart Ranch headquarters. She also purchases 480 acres from Erickson at the upper end of Wasson Canyon.
1927-1935 - Lockhart intensively develops the L/Heart Ranch. She begins to purchase tracts of rangeland that will eventually expand her holdings in the area to over 6,000 acres. Among the renovations and upgrades to the property include the construction of a bedroom addition on the main house, construction of a blacksmith shop, sheds, and a chicken house.
1936 - Lockhart and Ketchum - who was her housekeeper - receive final certificates for their homestead entries. In 1938 Lockhart will purchase Ketchum’s 640 acre homestead parcel.
1937 - Lockhart stores batteries in her cellar which power the first electricity at the ranch.
1955 - Lockhart sells her 6,034.75-acre ranch to Issac C. Tippets.
1980 - Ivan Tippetts sells portions of his ranch to the National Park Service, including the former L/Heart Ranch headquarters site.