Hahamongna is the rare spot in the Arroyo Seco at the foot of the San Gabriel Mountains where the mountainous watershed meets the urban plain. Periodically floods roar into this basin. Bounded on the north by the mountains and Jet Propulsion Laboratory and on the south by Devil's Gate Dam, Hahamongna contains five unique habitat zones that only exist in alluvial canyons near the mountains. Most sites like this in Southern California have been destroyed.

Don't let Hahamongna go the way of other lost environmental treasures in Southern California.

Walkabout 2011 Coverage


Altadena Patch

Pas Daily Photo


Winter Storms

Is this anyplace to put soccer fields?

The Meaning of Hahamongna

The original settlers of the region were sometimes called the Hahamongna Indians. The word means "Flowing Waters, Fruitful Valley" in the native Tongva language.

Hahamongna Walkabout II - March 31, 2012

It was a drizzlie day on Saturday, so some people stayed home and missed the Second Annual Hahamongna Walkabout. But now no one has an excuse because PCC student Jason Carman captured the presentations on digital video. Thanks, Jason!

To view the video highlights, just click on the related picture.

Tim Brick and Mary Barrie offer an overview of why Hahamongna is so special.Mr. Tree was there to wow the crowd with a wonderful impersonation.Michele Zack presented the history of Hahamongna.
Wendy Katagi of CDMSmith told participants about fish in the Arroyo.Tim Martinez has a wonderful way of talking about native plants and habitat.Kristen Farley and Brad Boman teamed up to cover geology and water resources.
Ryan Butler and Tom Budinger from LA County Flood Control District gave the scoop on the big sediment removal program.