Brooks Island sits in the central bay between Richmond and San Francisco, surrounded by one of the most densely developed metropolitan areas in the country. That it remains undeveloped is remarkable. Every other island of comparable size in the bay has been built upon, bridged to, or otherwise incorporated into the urban landscape. Brooks Island's preservation as a nature reserve makes it a time capsule of what the bay's islands looked like before European settlement -- native grassland, rocky shoreline, and the quiet that comes from being surrounded by water in the middle of a noisy world.

The Ohlone shellmound on Brooks Island is approximately 2,000 years old, a deposit of shells, tools, and cultural material left by the indigenous people who used the island for seasonal gathering and processing of shellfish. Shellmounds are among the most important archaeological sites in the Bay Area, representing thousands of years of indigenous habitation. Many have been destroyed by development. The Brooks Island shellmound, protected by the island's isolation and preserve status, remains intact -- a physical record of human life on the bay that predates every other story told about the region.

The restriction to guided tours is not arbitrary gatekeeping. Brooks Island's ecology is fragile -- nesting birds, including least terns, are easily disturbed by uncontrolled human access. The shellmound is vulnerable to casual collection and erosion. The naturalist-led tours, offered on scheduled dates, allow visitors to experience the island while minimizing impact. The tours typically include a boat crossing from the Richmond shoreline, a hike across the island's grasslands, and interpretation of the natural and cultural history. For a few hours, visitors stand on one of the last wild places in San Francisco Bay and look back at the cities that surround it.