What will happen to Glen Canyon if the government shuts down?

If the the government shuts down, the situation is confusing, but here is what I have been able to learn.  The Colorado River float trips WILL NOT RUN because this requires travel through the tunnel to the dam.  Due to security issues, no traffic will be allowed to use this roadway if the government shuts down. Tours of Glen Canyon Dam will not operate.

We are now told that Lake Powell boat tours, powerboats, lodging and houseboat rentals will SHUT DOWN COMPLETELY AT 9 P.M. ON APRIL 8.

If tours are canceled, or the park is closed, refunds will be given.

If I receive additional information, I will post it here.