Zion National Park has annual cliff closures for Peregrine Falcon Nesting.  This affects many of the popular cliffs for rock climbing in the park and include Angels Landing, Mt Kinesava, Tunnel Wall west, East Temple, Mt Spry, Issac, Mountain of the Sun, Great White Throne (climbs longer than 2 pitches), Sentinel, North Twin, and Middle Fork of Taylor Creek.  They go into effect on March 1st and get lifted in two phases.  Initially they close all cliffs with a history of nesting.  After monitoring  by park biologists they determine what cliffs have active nesting and keep those closed until the summer.  Check out our Zion Current Conditions page for more information on these closures and when they get lifted. Here is a link to the official Zion National Park press release.