In 1976, the newly formed Flathead County Park Board sent to the Montana State Land Board a recommendation that a 442-acre tract of state school trust land in Flathead County be classified as a natural area. The tract encompassed a large island (“the Big Island”) in the braided section of the Flathead River, at the confluence of the Flathead and Stillwater Rivers, and portions of near-by islands and mainland shore pieces. Flathead County committed to paying the state lease fee on the tract, and the County Park Board accepted responsibility for managing it as a natural area. The Land Board, accepted the recommendation.
The Chair of the new Park Board, and one of the most energetic proponents of this project, had been Owen Sowerwine. Sowerwine had previously been a member of the State Land Board. He was well known in the Flathead as an avid outdoorsman, a dedicated conservationist, and a civic leader. The Land Board recommended that the new natural area be named after Owen Sowerwine, who had died in January 1975. A public hearing on the proposed designation was held in May 1976 in the Community Room of the Conrad National Bank in Kalispell. The public was enthusiastic and the designation process moved forward. In 1978 the State Land Board designated the parcel as class 4 land (for “natural area use”), and the Owen Sowerwine Natural Area was established.
The official dedication ceremony took place September 9, 1978. An article in The Daily Inter Lake the following day begins: “It became official Saturday. A wild thicket enfolded in the coils of the Flathead and Stillwater Rivers is now protected under the name of Owen Sowerwine, the longtime Flathead Valley resident and conservationist who initiated the fight to preserve the area.”
Participants in the ceremony that Saturday gathered in the morning at the Outlaw Inn, and were taken in a bus donated by the Inn to a boat launch site on the Stillwater River. Volunteers from the Flathead County Search and Rescue ferried the participants to the Big Island in boats provided by Montana Fish and Game. The dedication ceremony was attended by members of Sowerwine’s family, then-Lieutenant Governor Ted Schwinden, members of the Flathead County Park Board, (then chaired by Arnold Jacobsen of Whitefish), and a number of other county and state officials.
The site was managed as a Natural Area by the Flathead County Park Board through 1995. In 1994 the yearly state lease fee had risen from the original $200 to $550, and Flathead County decided it could no longer afford to retain the lease. In 1996 Flathead Audubon stepped forward to assume the lease and manage the Area in order to maintain its status as a Natural Area.
When a new assessment in 1999 threatened an astronomical rise in the lease fee, Flathead Audubon joined with Montana Audubon to negotiate a long-term license for OSNA with a reasonable fee. Agreement was finally reached in the spring of 2001. Montana Audubon became the official license holder, and provided insurance for Audubon-sponsored activities at OSNA. Flathead Audubon paid the bulk of the yearly license fee and carried out the management of the Area.
When this license expired at the end of February 2010 a new 10-year license was signed. Montana Audubon was again the official license holder, while Flathead Audubon remained the on-site manager. In fall 2019, the license was reassigned to make Flathead Audubon and Montana Audubon the joint license holders of OSNA, with Flathead Audubon continuing its management role. The two Audubons together pay the yearly license fee for OSNA and share the management costs.
The original management plan for OSNA, the Owen Sowerwine Master Plan, was written in the late 1970s by the Flathead County Park Board. The forward to that plan, written by Sam Bibler, calls on the managers of OSNA “… to keep the heavy hand of man as much out of the management as possible, and to proceed as carefully and thoughtfully as possible.” With the signing of the first 10-year license in 2001 came the task of writing a new management plan for OSNA. Working together, Montana Audubon, Flathead Audubon, and the Montana Department of Natural Resources developed a new plan that is basically an updated version of the original management plan. This new OSNA Master Plan was officially adopted when it was approved by the Montana State Land Board in January, 2003.