El Rosario Monarch Butterfly Sanctuary (Santuario de Las Mariposas Monarca, El Rosario), accessible from Angangueo, is located near the tiny village of El Rosario. The easiest way to visit this ecological preserve is to book a guided bus or van tour from Mexico City or Morelia; arrangements can be made through travel agencies in those cities. Alternatively, tour guides can be hired in Angangueo, and the Hotel Albergue Don Bruno, in the center of town at Calle Morelos #92, has basic rooms for an overnight stay. From Angangueo the slow, steep route to the sanctuary by truck or four-wheel-drive vehicle takes about an hour.
On cold, cloudy days the butterflies cling to tree branches; when the sun is out they're more active. The best chance of seeing impressive swarms of monarchs is February into early March. Wear sturdy, comfortable walking shoes and dress appropriately for the weather. On weekends the refuge is often crowded with visiting Mexico City residents; plan a trip during the week if possible.
Note: Check the U.S. State Department's latest Mexico Travel Warning advisory before planning any trip to this region.