On the Pacific Coast of the Baja Peninsula, the Laguna San Ignacio complex provides Mexico’s primary gray whale breeding and calving habitat. The lagoon also harbors sea turtles, peregrine falcons, ospreys, and hundreds of thousands of migratory shorebirds and waterfowl. In 2009, when Resources Legacy Fund and the Laguna San Ignacio Conservation Alliance were developing strategic conservation plans for the region, they learned that Mitsubishi and the Mexican government had quietly entered into a formal partnership to establish a salt mine that would have devoted a massive portion of the lagoon to salt extraction ponds and a shipping pier. The Alliance negotiated with the Mexican government to secure conservation status for 200,000 acres of federal lands and 159 miles of lagoon coastline. Then RLF grantee and Alliance member Pronatura Noroeste entered into a long-term agreement with the government to manage the federal lands for conservation purposes. Finally, RLF established a reserve fund to cover ongoing costs of protecting lagoon lands. Laguna San Ignacio embodies the RLF approach across northwest Mexico: engage collaboratively with local communities, conservation organizations, and private landowners, while building capacity, advancing policy, and acquiring land. The result? Nearly 1,000 square miles of unparalleled habitat protected.