Scientists estimate that close to a billion monarch butterflies historically overwintered in montane oyamel fir forests about two hours west of Mexico City. Numbers of monarchs at Mexico’s butterfly reserves have declined steeply in the last few years with estimates at about 35 million for the 2013-2014 season. We hope that further decline can be stopped by cooperative efforts in Mexico, Canada, and the US. All three countries provide habitat for the monarch butterfly population that involves a multi-generational life cycle that involves a long-distance migration southward to Mexico each fall. We had the opportunity to visit El Capulin and Piedra Herrada sanctuaries in Mexico State in March this year with a group of travelers from Denver Botanic Gardens. Even though this year’s numbers are way down, the sight of thousands of monarchs filling the sky at once remains an impressive sight.