The western peak of Mount Tamalpais, bulldozed during the Cold War to make way for an Air Force station where soldiers watched the skies for Soviet bombers, is still home to a slew of crumbling structures, power lines and concrete slabs. Now, the Marin Municipal Water District, which has jurisdiction over the land, and the Golden Gate National Parks Conservancy are collaborating to restore the peak. “It was very shocking, the first time I visited the site,” China Granger, who interned last summer for the ONE Tam campaign, said during a panel presentation on the restoration project last Thursday in Mill Valley. “It’s all rolling hills, and then you get up there and it’s completely flat. It’s easy to feel that the area was mistreated, and you want to completely restore the mountain.” The more than 100-acre military base was closed in 1980 after the radar technology used there became obsolete. Though some structures were removed, foundations, roads and other infrastructure have stood untouched for the last four decades.

Claire Mooney, deputy director of the Golden Gate National Parks Conservancy’s projects and design department, said a combined effort by the National Park Service and the water district to restore the land began shortly after the base closed. But contamination in soil and other materials—primarily from lead, asbestos and petroleum products—required more funds than were available. About a year ago, the water district and the conservancy launched a new effort, each allocating $225,000 to conduct a feasibility study that would provide a basis for design alternatives. Their team included staff from both agencies as well as contractors with expertise in ecology, geology, construction, engineering and more. That study is expected to come out this winter. At last week’s presentation, Ms. Mooney unveiled the goals for the project as well as two design concepts. Both alternatives would remove all 12 remaining structures—including an old bowling alley—and excavate two other areas with contaminated soil. Both would take out power lines, power poles and fences, and recover some of the mountain top’s original soil, which the military dispersed around the mountain, in order to fill and regrade the peak to restore its natural topography and hydrology. Enhancing native plant habitat and wetland and water infiltration is another major objective of both alternatives, which would likely also include some signage that explains the historical significance of the site. But the alternatives differ in scope and cost. The least intensive would completely restore six acres and would cost an estimated $9 million; the more extensive option targets over 18 acres and could cost $13 million. “These two concepts are really the bookends, or even placeholders, for the restoration project,” Mike Swezy, the restoration project manager for the water district, said on Thursday. After receiving public input, the water district board will choose a preferred alternative by January or February. Work is slated to begin in 2020.