The river begins at Outlet Bay on Pakashkan Lake about 45 kilometres (28 mi) northeast of the community of Upsala.

The two combine again to form the river Allan Water at the community of Allanwater Bridge, the location of Allanwater Bridge railway station, served by Via Rail transcontinental Canadian trains, on the Canadian National Railway transcontinental main line.

It was established in May 1989 to protect a recreational waterway that also provides an important link with other provincial parks and conservation areas.

Notable aspects include a variety of interesting glacial features and 10 known rock art sites.

The park is used for recreational activities such as boating, canoeing, fishing, hiking, swimming, and hunting.