Before the dam, there was a town. Searsville was founded in 1854 by John H. Sears, who built a hotel to support the local logging industry. The town sat at the confluence of Corte Madera Creek, Sausal Creek, Dennis Martin Creek, and Alambique Creek, where wetlands once filtered water flowing toward San Francisquito Creek. The Spring Valley Water Company built the dam, and Searsville was partially inundated. The town had already been declining as the surrounding forests were logged out, but the dam sealed its fate. Today the reservoir sits at 341 feet elevation within the Jasper Ridge Biological Preserve, owned and operated by Stanford.

Searsville Dam is the only complete barrier to fish migration on the mainstem of San Francisquito Creek. Before the dam, steelhead trout and likely coho salmon ran up these creeks to spawn. Edgar Batchelder, whose father became dam caretaker in 1897, recalled that when the dam overflowed in winter, salmon would swim to its base, where his father could spear them with a pitchfork. A 2002 study estimated that removing the dam could restore ten miles of anadromous steelhead habitat. A genetics study confirmed that the creek's steelhead are native, not hatchery stock. Environmental groups have pushed for dam removal. Stanford's Jasper Ridge Advisory Committee has weighed alternatives ranging from full removal to dredging to letting the reservoir fill naturally with sediment.

In a twist that elevates a local dam dispute to geological significance, the Anthropocene Working Group selected Searsville Dam and its reservoir as a candidate location for a 'golden spike' -- a formal marker indicating the boundary between the Holocene epoch and the Anthropocene, the proposed geological era defined by human impact on Earth's systems. The sediment layers in the reservoir contain a readable record of mid-twentieth-century changes: nuclear fallout particles, industrial chemicals, altered sedimentation rates. If selected, Searsville Dam would mark not just the place where a logging town drowned but the place where geologists formally acknowledged that humanity had become a geological force.