In 2012, California completed its marine protected area (MPA) planning and designation process, yielding a network of 124 MPAs from the Mexican border to Oregon. The management effort that has followed is comprehensive and strategic, with a focus on scientific monitoring, interagency coordination, public education and outreach, and enforcement. Initial monitoring results show more and bigger fish, especially in older MPAs where the benefits of limiting fishing have had longer to accrue. Today, California state agencies increasingly acknowledge and contemplate MPA protections in their permitting decisions, as regional and statewide outreach and education efforts enhance public awareness, social capital and stewardship. While enforcement remains challenging in a marine region as large and populous as California, the state has taken important steps to promote compliance with new MPA regulations and—with the support of the state legislature—has strengthened laws to address poaching. As new MPAs are established throughout the world in accordance with global targets, California's post-designation efforts provide a valuable and educational case study for local, national and international MPA managers.