From North Cascades NP:
The Cascade River Road in North Cascades National Park will close to vehicular traffic at Hard Creek Bridge (MP 12.7) beginning on Sept. 1. The road will be open September 5-7 during the holiday weekend. The road will be closed again on September 8 through project completion in mid-October. Any cars left up-valley of the construction will not be able to exit Cascade River Road until the project is complete.
Foot or bicycle traffic may be allowed, but may encounter delays and must obey direction provided by construction crews to ensure their safety through the construction zone.
FHWA will be closing the road to accommodate bridge installation and permanent road repairs. The Cascade River Road provides access to Johannesburg Camp and the Cascade Pass Trail.
For additional information about the Cascade Pass Trail, call 360-854-7245 or visit http://www.nps.gov/noca/planyourvisit/cascade-pass-trail.htm
All overnight stays in the backcountry require a free permit, which must be obtained in person and is issued on a first come first served basis.