Sanctuary River Bridge Environmental Assessment
June 25, 2012
Contact: Steve Carwile
The National Park Service (NPS), in cooperation with the Federal Highway Administration (FHWA), is considering a road rehabilitation project on two sections of the Denali Park Road in Denali National Park and Preserve.
Between Mile 24.3 and 25.0 (Sanctuary Saddle), the NPS is proposing to address drainage issues and soil movement from the backslope (area above the road). If approved, the project would also add gravel to the road surface, replace ageing culverts and reshape the road so that the dimensions do not exceed the standard for maximum road width.
At Mile 4.5 the NPS proposes to complete a road rehabilitation project begun in 2008. The backslope would be stabilized by spreading rock across the surface. This project, if approved, would take place during the summer of 2013.
The Environmental Assessment (EA) evaluates two action alternatives. Under Alternative 2, the preferred alternative, the NPS would install an additional 1,256 linear feet of rock at Mile 4.5. At the Sanctuary Saddle, the NPS would install about 300 feet of underdrain under the ditch and approximately 1,450 linear feet of rock on the backslope.
Under Alternative 3, no additional riprap would be installed at Mile 4.5 or at the Sanctuary Saddle. About 2,300 feet of underdrain under the ditch would be installed at the Sanctuary Saddle.
Under both action alternatives, the Sanctuary Saddle section of road would be standardized to a width of 26 feet, additional gravel would be added to the road surface, and the road would be smoothed.
The NPS has published an (EA) for this project entitled "Rehabilitation of the Park Road in the Sanctuary Saddle and 4.5 Mile Areas." It is available on the NPS planning website at http://parkplanning.nps.gov. The EA analyzes the impacts of the "No Action" alternative and the two action alternatives. It was completed in accordance with the National Environmental Policy Act of 1969 and the regulations of the Council on Environmental Quality (40 CFR 1508.9).
Comments on the EA may be submitted through Monday, July 23, 2012, preferably via the web site at http://parkplanning.nps.gov. Comments may also be mailed to: Superintendent, Attn: Sanctuary EA, Denali National Park and Preserve, P.O. Box 9, Denali Park, AK 99755 or faxed to 907-683-9612. For questions or paper copies of the EA, please contact Steve Carwile at 907-644-3612 or via email.