In relatively well-developed areas, such as western Contra Costa County, finding mitigation sites can be problematic. Uplands with potential for restoration are often earmarked for other development projects, making them cost-prohibitive for mitigation work. At Mariner’s Walk, in Martinez, Zentner Planning and Ecology worked with RWQCB staff to identify local mitigation sites for an Olson Company project. When no readily available sites were found, we identified a mitigation site in neighboring Solano County, across the Carquinez Strait. Although initially reluctant to cross County borders, RWQCB staff were persuaded by our ecological analyses demonstrating the similarities between the development and mitigation sites and approved the project.