The monarchs spend the winter in the tops of a handful of forested mountaintops in a small region of Michoacan and the state of Mexico.
It can be a nice hike or horseback ride to get up to where they are, but you know you are in the right spot when you see masses of butterflies covering limbs and trunks of oyamel fir trees in clusters of tightly huddled monarchs.
It is an amazing site.
Monarch butterflies (Danaus plexippus) clustered on oyamel fir tree, Cerro Pelon, Monarch Butterfly Biosphere Reserve, Mexico. Canon 7D Mark II. 538mm. ISO 1600. F/9 @ 1/250 second. EV +1.