The Parks Conservancy in partnership with the National Park Service engaged 34,484 volunteers who put in 513,884 hours in 2011 alone. That kind of work would cost $10.9 million on the open market.

The Chronicle previews a visit by filmmaker Ken Burns and co-producer Dayton Duncan for "Parks for All," a conference on engaging all communities in national parks. Hosted by the Parks Conservancy and KQED, the event launches "Untold Stories," an outreach initiative to support Burns's forthcoming documentary "The National Parks: America's Best Idea."

The Chronicle profiles the Crissy Field Center's 2008 Community Heroes Award recipients, four inspiring Bay Area individuals and organizations working to improve their environments.

May 2011 marks the 10th anniversary of the $34 million restoration of Crissy Field, a 1.3-mile stretch of shoreline between the new Crissy Field Center on the east and the Warming Hut on the west - one of the great vistas anywhere.

Three proposals for cultural institutions are competing to be chosen as worthy of the spectacular, but currently underutilized, site, which is now home to a sporting goods store.

Three very different proposals were presented Monday for one of the most potentially memorable sites in San Francisco - 8 acres facing the marsh at Crissy Field, downhill from the Presidio's Main Post.

In its coverage of Earth Day-related community events, the Chronicle highlights Crissy Field Center's "Earth Stroll", an opportunity for families to walk Crissy Field, participate in eco-games, learn about the environment, and enjoy a beautiful spring day.

In advance of the ribbon-cutting on June 14, the Chronicle features on its front page an in-depth look at the remarkable rehabilitation and transformation of Fort Baker from military post to a beautiful national park that "looks like something out of a postcard."

The Chronicle showcases the remarkable revitalization of the historic gardens on Alcatraz, an effort spearheaded by the Garden Conservancy, Golden Gate National Parks Conservancy, and the National Park Service. After 40 years of neglect, volunteers are helping bring color and vibrancy back to the Rock.

Discussing the three semifinalists submitting final proposals to create a cultural venue to replace the Presidio's former commissary building, today's Sports Basement store.