The Kahiltna Flats/Petersville IBA extends east from Treasure Creek to near the Petersville Road, south of the Kahiltna Glacier. It is dominated by the Kahiltna River and its floodplains to the west.
Several areas within this IBA are important to different species. The Kahiltna floodplain contains one of the largest concentrations of trumpeter swan nesting sites in upper Cook Inlet. A relatively small portion of the wetlands at the base of the Kahiltna Glacier is used by significant numbers of molting post-breeders and young-of-the-year Tule Greater White-fronted Geese.
The Petersville Road BBS route ranked number 2 (tied with 2 other sites: Swan Lake and Anchor River) in the protocol to identify migratory land bird habitats that support significant multi-species assemblages and concentrations. This IBA supports eight Partners in Flight priority species (Gray-cheeked Thrush; Golden-crowned Sparrow; Varied Thrush; Bohemian Waxwing; Arctic Warbler; White-winged Ccrossbill), as well as two Audubon Alaska WatchList species of conservation concern: the Blackpoll Warbler and Olive-sided Flycatcher.
Disturbance to birds, natural resource extraction industry, intensified forest management, recreation/tourism, and expanded road access.