Marin Open Space Trust Board of Directors

Marin Open Space Trust’s board of directors come from all parts of Marin and have diverse backgrounds, but each share one goal: to preserve Marin’s open space. They generously commit their expertise, time, and passion.


Bill Long, Chair

“Preserving and enjoying Marin’s open space has been my passion ever since I arrived here more than 50 years ago.”

Bill Long is a retired engineer from Novato, who moved to Marin in 1969. He has a very extensive background in public service, having volunteered his time and energies over the years to many worthwhile causes, including working on the ballot measure that successfully created the Marin County Parks and Open Space District in 1972, and then serving on its commission for ten years. Bill also serves as chair emeritus of the Bay Area Ridge Trail Council and is a board member of the San Francisco Bay Trail. Bill is a lifelong sailor, avid hiker, and former Boy Scout leader.

David Hansen, Vice Chair

“Securing funding to protect the last undeveloped lands and complete the dream of a permanent greenbelt in Marin County can be done with MOST’s leadership.”

David Hansen is retired from a 33-year career preserving and managing over 70,000 acres of open space and farmland in the Bay Area. He was planner, land acquisition manager, and trail designer for the Marin County Open Space District; land manager for the Midpeninsula Regional Open Space District; and first general manager of the Sonoma County Agricultural Preservation and Open Space District. David was a co-founder and board member of the Bay Area Ridge Trail Council, Bay Area Open Space Council, Trail Center, and Whole Access. He is a volunteer and emeritus board member of the nonprofits LandPaths, Sonoma Mountain Preservation, and Friends of the Petaluma River. He also serves as an advisor for the Santa Rosa SE Greenway Committee.

Ann Thomas, Secretary and Treasurer

“As development pressure grows it is all the more crucial to secure parkland and open space for future generations.”

Ann Thomas had an earlier career in journalism and advertising, helped raise funds for local schools (when her children were students) as a director and one-time board president of the Kentfield Schools Foundation, and has been an advocate for Marin open space for the past two decades. She helped organize the campaign to save the Bahia forest and wetlands and, as a member of the Marin Baylands Advocates, assisted in the preservation of a number of bayland sites. Ann was a longtime member of the Kentfield Planning Advisory Board, served as a Marin Conservation League board member, and currently sits on the board of the Friends of Corte Madera Creek Watershed. She is a Corte Madera resident.

Ralph Mihan, Legal Advisor

“The preservation and recreational use of parks and refuges nationally and statewide, and the open space of the great county of Marin, are my lifelong passion and commitment. The future expansion, preservation, and public use of parks and open space in Marin is a major objective of mine.”

Ralph Mihan is a lifelong resident of Marin who grew up in San Anselmo and now resides in west San Rafael. He has hiked and enjoyed Marin open space and parks since early childhood. Ralph retired from a 37-year career as regional legal counsel to the western region of the National Park Service (62 national parks) and the US Fish and Wildlife Service (32 wildlife refuges). During his career he was involved in the acquisition of more than 1 million acres of land and the management of those lands for public recreational use and preservation. He has been active with many Marin and Bay Area parks and open space organizations, including as commissioner (and often chair) of the San Rafael Park and Recreation Commission (38 years), and board member of the Bay Area Ridge Trail Council (14 years), Point Reyes National Seashore Association (14 years, and now on its council of advisors), and Marin Conservation League (2 years).

Joyce Applen

“In my early Marin years, I developed an appreciation of the glorious open spaces throughout this beautiful county, hiking with Mrs. Terwilliger and several other hiking groups.”

Joyce Applen is an active conservationist living in Novato. She has lived in Marin since 1967 and has been a volunteer in the preservation of open space since the early 1970s when a citizens committee convinced Marin County voters to pass a ballot measure creating the Marin County Open Space District. As chair of the Marin Conservation League committee to preserve Mt. Burdell, she worked with the Novato planning staff to develop an open space plan for the entire Novato area. When serving on committees appointed by the city council to study the reuse of Hamilton Air Force Base, she opposed commercial aviation, and the runways are now being restored as wetlands. Joyce has been active as a real estate broker since 1980. She has represented the Marin Baylands in its acquisition of several properties threatened by development.

Jonathan Braun

“I have long believed it is vitally important to secure lands of high open space value in perpetuity for the benefit of the ecosystem and the enjoyment of present and future generations.”

Jonathan Braun is a lifelong resident of San Anselmo. He became involved with land preservation in the late 1970s when development threatened the hilltop above his family’s home. That was the catalyst for many decades of volunteer participation in local conservation initiatives. In 1981 Jonathan worked with a citizens group to create the San Anselmo Open Space Committee. He still serves as a member and has been chair and co-chair for more than 32 of the committee’s 40 years. He has been involved in many land-use issues and led fundraising campaigns for the purchase of public open space. For the last four decades, he has been a potter, woodworker, and classical guitarist.

Elizabeth Byers

“I love hiking in Marin’s awe-inspiring open space lands, and feel so fortunate to live here. Working with MOST provides me an opportunity to participate in the ongoing work of saving important places in Marin.”

A Mill Valley resident, Elizabeth Byers has lived in Marin County since 1989, and is a native northern Californian. She worked in land conservation for decades: as a project manager and land trust program director at The Trust for Public Land (TPL) for 16 years and as a long-term consultant for the Garden Conservancy, Bay Area Ridge Trail Council, and TPL. This consulting work included co-authoring the second edition of The Conservation Easement Handbook, published by TPL and the Land Trust Alliance. In 2019 she updated the Bay Area Ridge Trail guidebook after hiking the 375-mile trail. Elizabeth has a BS in Conservation of Natural Resources and an MLA in Environmental Planning from UC Berkeley. She is a past board member of the Bay Area Ridge Trail Council and San Anselmo Open Space Committee.

Don Dickenson

Don Dickenson was born in San Francisco but has resided most of his life in Marin County—for over 30 years in the Dominican neighborhood of San Rafael. He has bachelor’s and master’s degrees from the College of Environmental Design at UC Berkeley. Don retired in 1999 after working for 25 years as a city planner for local public agencies. His projects included the artist Christo’s “Running Fence” and film director George Lucas’ Skywalker Ranch. For 15 years he was the director of planning and building for the City of Mill Valley. Don also served a total of 13 years on the board of the Marin Conservation League and was previously on the board of Greenbelt Alliance and a member of the executive committee of the Marin Group of the Sierra Club. He was a founding member and president of CAPS (Citizen Advocates for Preservation of St. Vincent’s/Silviera) and a founding member of the Save Gold Hill Committee. Don has served on the Grand Jury and the Marin County Planning Commission since 2003 as a representative of the First District and then as an at-large commissioner.

Steve Petterle

“It’s not an accident that I’ve spent my career protecting watersheds, open spaces, and natural areas. These areas are critical to the emotional and physical survival of the human species.”

Steve Petterle is a native Marin County resident who learned to appreciate open space in Marin County while hiking the hills above Dominican in San Rafael. Steve has a BS degree from UC Davis in environmental planning and management. He became a licensed landscape architect in 1979 and has been involved in managing public lands for 43 years. He was a land manager for the Marin Municipal Water District from 1983 until 1990, managing its 22,000-acre watershed. After a brief stint in the private sector consulting in land/resource management and landscape architecture, he moved to the Marin County Open Space District, where he was involved in acquisition and management of open space lands. Steve retired from his position at the county as principal landscape architect in 2020, but remains active in public service, also sitting on the boards of the North Marin Water District and Frank Lloyd Wright Civic Center Conservancy.