Mexico’s Monarch Butterfly Sanctuary at Piedra Herrada

This past week I traveled roughly 2.5 hours west of Mexico City to visit the Santuario Mariposa Monarca (Monarch Butterfly Sanctuary) at Piedra Herrada in Mexico state. Heading out of Mexico City we traveled west through Santa Fe — Mexico City’s very modern business district. As we made our way toward Piedra Herrada and the nearby town of Valle de Bravo, I was surprised to discover that Mexico state is actually the source of much of the city’s pollution and smog. We passed factories emitting thick clouds of smoke and for as far as I could see the sky remained a smoggy shade of gray. As I stared out the bus window, I couldn’t help but wonder how there could be a butterfly sanctuary and nature reserve just a couple of hours away.

Designated a UNESCO World Heritage Site, Mexico’s Monarch Butterfly Biosphere Reserve is located in a mountainous region roughly 100 km (62 miles) northwest of Mexico City. The protected area covers more than 200 sq miles of Mexico and Michoacán state. Every Autumn millions of Monarch butterflies migrate from as far north as Canada to central Mexico where they stay clustered within small areas of the reserve until the following Spring when their journey begins all over again. The 8 month migration takes them all the way to Eastern Canada and back, during which time four successive generations are born and die. How the final generation makes it back to the same forested area year after year remains a mystery.

Despite my earlier doubts, we arrived to sunshine and clear skies at the Piedra Herrada Butterfly Sanctuary. As we drove up the final stretch of road toward the entrance to the reserve I began to notice butterflies fluttering around outside the bus windows. The closer we got the more there were until the entire roadway was filled with orange and black Monarch butterflies — some the size of small birds. We got out of the bus and walked, slower and more carefully than usual, against the steady stream of butterflies all the while trying not to disrupt their flight as they headed down to the nearby natural spring that serves as a butterfly watering hole — a journey they make daily around midday. I was in awe, this was exactly what I had hoped to see while visiting the sanctuary and we hadn’t even arrived yet.

The Monarch Butterfly Sanctuary at Piedra Herrada (Los Saucos, state of Mexico) is located out in the countryside about a 30 minute drive from the nearby small town of Valle de Bravo. Like many tourist sites in Mexico, the entranceway to the reserve is lined with vendors offering a variety of souvenirs and snacks. We made our way inside the gate where we were divided up into groups and assigned a local guide. It’s a challenging 45 minute hike up the mountain along dirt paths to reach the reserve’s main observation point. Visitors have the option of hiking or hiring a horse and guide for 150 pesos ($12). Though not terribly difficult, it’s a dirty and dusty climb. Some of the people in our group had a harder time than others and a few weren’t able to make it up at all.

Interestingly, at the base of the mountain we didn’t see many butterflies – nothing compared to what we encountered along the main road on our way in – but we began to see more and more of them as we got closer to the observation point. When we finally made it up to the top they were everywhere, carpeting the trees and branches and swarming overhead. But what really surprised me was the way they cluster together and hang from the trees and branches likes bats. From a distance the clusters resemble beehives but as you get closer it’s possible to make out the individual butterflies.

We stood at the top of the mountain taking it all in while butterflies fluttered overhead and took turns landing on our shoulders and arms. Every now and then the wind would blow, rustling the leaves and causing all of the butterflies to take flight in what seemed like a sudden explosion of orange and black. It was a specatcular display, and all the more impressive when seen up close and in person.

After departing the butterfly sanctuary at Piedra Herrada we spent a few hours in the small lakeside Pueblo Magico (Magic Town) of Valle de Bravo.

Getting There
The Monarch Butterfly Sanctuary at Piedra Herrada can be visited independently or as part of an organized tour from nearby Valle de Bravo or Mexico City. Public buses travel between Mexico City and Valle de Bravo, after which you may need to arrange for taxi service or private transportation to the sanctuary. Mexico’s Monarch Butterfly Biosphere Reserve is best visited between mid-November and early March. It’s an easy day trip from many of the cities and towns in the region and you’ll likely have a few hours left over to tour Valle de Bravo. Other access points to the reserve include the El Rosario Monarch Butterfly Sanctuary and the Sierra Chincua Sanctuary near Angangueo, Michoacán.