The mission of the Eastern Sierra Avalanche Center is to inform and educate the public on avalanche conditions in the Eastern Sierra Nevada mountains of California.

The Friends of Eastern Sierra Avalanche Center is a 501(c)3 non-profit organization overseen by a volunteer Board of Directors, outlined below. For general information, please email

ESAC employs avalanche forecasters to provide daily avalanche advisories and field observations. An administrative coordinator and education coordinator support the forecasters and the board of directors in fulfilling our mission and expanding opportunities for local community members.




Chris Engelhardt, Forecaster

The Eastern Sierra has always been a special place to Chris, he grew up skiing at Mammoth and after college returned to ski patrol at Mammoth for four winters. Chris has also worked a guide/patrol and as the snow safety director at Silverton Mountain in the San Juan Mountains of Colorado, forecasted and guided heli-skiing in the Chugach and Kenai Ranges of Alaska, and guided skiing on Hokkaido, Japan. Chris has worked as a ski/snow professional since 1999 and is experienced with both maritime and continental snowpack.




Steve Mace, Forecaster

Steve grew up skiing in Golden, Colorado. He began to venture outside the gates in his mid teens and never looked back. While attending college in Durango, Colorado, he continued to push his skills and knowledge earning his turns in the San Juan mountains. He has skied across the globe from Japan to the Himalaya where he helped start a ski school in Gulmarg, Kashmir. More recently Steve has worked as a ski guide in the Wallowa Mountains of eastern Oregon as well as a member of the Snow Safety department at Mt Hood Meadows. When Steve isn’t skiing he spends his time guiding raft trips on the Colorado River through the Grand Canyon.


Mike Phillips, Education Coordinator

Mike is the Education Coordinator for the Eastern Sierra Avalanche Center. Mike grew up skiing and snowboarding on icy ski area slopes in New England and far prefers the softer snow and bigger mountains of the West. He has worked for the Mammoth Mountain Ski Patrol since 2010 and is a lead member of the patrol’s Weather and Avalanche Safety Program. Mike has also taught AIARE avalanche courses in the Mammoth area since 2016. While powder skiing sure is great, Mike always looks forward to spring ski touring and corn snow in the High Sierra.




Rachel Drattler, Administrative Coordinator

Rachel grew up in the Northeast and moved to California after college to pursue her passion for climbing. With a degree in Human Ecology, Rachel has dabbled in numerous industries, traveled extensively throughout the U.S. and abroad in pursuit of remote climbing and skiing adventures. After years of working as an outdoor educator, Rachel has settled into the Eastern Sierra where she now calls June Lake, “home”. When not bounding about the Eastside, her seasonal migration leads her back to Boulder, Utah where she works as an instructor for Boulder Outdoor Survival School.



Board of Directors

Nate Greenberg – President

Forrest Cross – Vice President

Ann Piersall Logan – Secretary

Neil Satterfield – Treasurer

Howie Schwartz

Allan Pietrasanta

Michelle Mather

McKenzie Long

Gabe Taylor


Walter Rosenthal – President in memoriam

Walter Rosenthal was the Snow and Avalanche Analyst for Mammoth Mountain, a remote sensing expert for the U.S. Army Cold Regions Research and Engineering Laboratory and a researcher at the Institute of Computational Earth System Science, University of California, Santa Barbara. He specialized in remote sensing of snow and snowpack processes related to sintering and avalanches. As a private consultant he provided operational subresolution snow mapping algorithms and programs to the U.S. Army Cold Regions Research and Engineering Laboratory from 1995 through 2002. Both the Army and the National Weather Service’s National Operational Hydrologic Remote Sensing Center employ his algorithms and are expanding their use to daily operational snow cover maps over North America.

Walter tragically lost his life while trying to save the lives of others in 2006. He was a vital force in the development of ESAC and is dearly missed.