The first settlers to pre-empt land in this area were farmers, one of whom started milling lumber in 1870. From 1870 to 1910, a succession of sawmills came into operation and with them, the community grew. Thomas Kilby came to Harrison Mills in 1902 and by 1904, had built a three-story building consisting of a general store and hotel. His son, Acton and wife, Jessie ran this operation until their retirement in 1976. The Provincial Government acquired this area. Today, the general store is a museum and is operated by the Ministry responsible for Tourism. The beach area has been developed into a riverside park with 22 campsites, a small day-use area, and a boat launch under the jurisdiction of BC Parks.
The Harrison and Fraser Rivers served as major transportation routes for the local First Nations population. In the mid to late 1800s, the Fraser River and Cariboo gold rushes created considerable activity along the Harrison River, near the site of this historic park.
The park lies within the Coastal Western Hemlock biogeoclimatic zone and is representative of the Fraser floodplain landscape. Upland vegetation includes cottonwood, poplar, alder, and willow while the understory consists largely of red currant and salmonberry.
Kilby Park is a designated British Columbia Wildlife Watch area. It is an excellent location to view large concentrations of wintering Bald Eagles as well as graceful trumpeter swans that migrate to the area from Alaska. Other common bird species to the park area include ravens, geese, eagles, swans, finches, chickadees and jays. Coho and Spring salmon can be found in Harrison River which borders the park.