A cell phone study by Point Blue Conservation Science will shine light on where visitors to Stinson Beach travel from as part of an effort to preserve the beach as a destination for disadvantaged communities as sea levels rise. Last week, county supervisors extended a $55,000 contract with Point Blue, which is working with the telecommunications company Air Sage to collect location data using the point of origin of cell phones. The study cross-references the origin point with census information on race, ethnicity and income to understand which communities are visiting the park and during which weather patterns. The Marin County Community Development Agency says the study will help assess the value of Stinson Beach as a climate sanctuary for disadvantaged communities. “It’s very hard to quantify beach use,” said Jack Liebster, a senior planning manager with the Community Development Agency. “This is part of a resource we’re trying to protect, and understanding how valuable it is, and to whom, is vital.” During the summer, when heatwaves envelop inland regions, Stinson Beach becomes a refuge for communities with less access to open water and parks. Point Blue estimates that Stinson received over 3 million visitors between 2017 and 2021, half of them coming from Marin and the other half from nearly every county in California, but primarily from the San Francisco and Sacramento metropolitan areas. Thirty-seven percent of the visitors were not white: 41 percent were Hispanic, 35 percent were Asian, 10 percent were Black and 12 percent identified as another ethnicity. Sam Veloz, Point Blue’s director of ecoinformatics and climate solutions, wonders how the reliance on Stinson Beach as a climate sanctuary will evolve as climate change worsens. “With this project, we are asking ourselves: ‘Can we provide recreation opportunities for locals and disadvantaged communities while also making our ecosystem healthier?’” he said. The study, which will be completed by March, is part of the county’s work to develop guidelines for projects that adapt to sea-level rise, from near-term solutions like education and emergency preparedness to medium-term solutions like bolstering existing structures and longer-term solutions like elevating and moving back structures. That work, part of the Sea-level Marin Adaptation Response Team, or C-SMART, has a newer arm called the Stinson Beach Adaptation and Resilience Collaboration. Isaac Pearlman, a planner who is leading the Stinson Beach effort, said the cell phone study will also help his agency “identify specific communities in Marin County, including underserved ones, which frequently visit Stinson Beach and that are important to actively engage in the [ARC project].” Phase one of the Stinson ARC, which began in August and will wrap up this year, produced a vulnerability assessment of the town’s infrastructure that showed that sea levels could rise 70 inches over the next 80 years, putting over 700 homes at risk. The second phase will focus on drafting adaptation strategies with continued input from the community. The final phase will produce a finished adaptation report that identifies funding possibilities.