Once you reach the sanctuary you pay about $2 apiece for a guide to lead you up a steep path to where the monarchs roost. What looks like clumps of dead brown leaves in the tree is actually thousands, if not millions of butterflies huddling together for warmth as they wait for the sun to come out.

Sanctuario de Mariposas, El Rosario, Michoacan, Mexico - December 30, 2000