Federal workers and contractors forced to stay home or work without pay are experiencing mounting stress from the impasse.
Roads that were passable at the time of the shutdown would remain open unless conditions worsened, park spokeswoman Kyle Patterson said.
Colorado's U.S. senators both voted Monday in favor of a temporary spending deal that allowed the federal government to reopen.
The U.S. Senate voted Monday to finance the government through February 8. A House vote is pending.