Where to Find Monarch Butterfly Roosts in the Bay Area

It’s that time of year again—the monarch butterfly migration is underway. In the coming weeks, these flight weary beauties will arrive throughout California to settle in before winter. Get excited, this is your best chance to witness one of the greatest natural phenomena in the insect world.

It all starts in late summer when a unique generation of monarch butterfly are born that can live up to eight months (as opposed to the typical six weeks). Unlike the previous generations, these young butterflies know innately from birth that it’s time to move south from their northern habitat. So, off they go, flying up to 2,000 miles and as high as 10,000 ft. to complete one of the longest known insect migrations on the planet.

How do they know where to go? Well, no one knows for sure. What we do know is that the Rocky Mountains offer the largest handrail for these migrants, bisecting the continent and forcefully directing traffic. Monarchs east of the Rockies work their way down to Mexico, while those in the west head to the central coast of California.

Once they’ve reached their final destinations, monarchs form clusters called “roosts,” typically on large trees out of the wind. There, they enter a state of hibernation and rest until it’s warm enough to begin their reproductive cycles. Roosts, in some parts of the state, can harbor thousands of sleeping butterfly.

Exciting, eh? There’s a whole kaleidoscope of butterflies headed our way right now (believe it or not, that’s what a group of butterflies is called) and you’ll be able to witness their arrival. So, where do you go to see this migration? Here are a few of our favorite spots to see monarch butterfly roosts (we suggest calling beforehand to be sure the roosts have formed):