A massive, state-proposed, roador railroadbuilding project will, if constructed, bisect the Toklat Basin area in and adjacent to Denali National Park and Preserve, along one of three proposed routes.If construction occurs, the road and its associated gravel pits will affect hundreds of pristine waterbodies, aquatic habitat, and wetlands.At particular risk are spring-fed, gravel-bed streams, which act as salmon spawning, rearing, and overwintering areas.A basic and severe lack of knowledge ofthe water resources along this corridor seriously threatens the National Park Service's (NPS's)ability to analyze, manage, and protect this area and subsequently mitigate impacts if this road construction occurs.In response, acomprehensive study was initiated in 2004to determine baseline water quality and physical hydrology information for five major rivers and streams in the Toklat Basin-the Sushana River, the East Fork River, Wigand Creek, the Toklat River, and the Clearwater Fork River