You are omitting a significant fact; that is, the restrictions will be
temporary during a period where there are high-interest events taking
place.

You bet they can issue temporary restrictions based on a high-traffic
event, ramp capacity, and the challenging topography of that airport.

Note also that they are limiting even IFR arrivals.

It is not without precedent.

wrote:

Can they close an airport to all VFR traffic? This is what they're
doing at Friedman Memorial Airport at Hailey, Idaho [HLE].

Link to the article:
http://www.mtexpress.com/index2.php?...&ID=2005102705