The Golden Gate National Parks Conservancy has announced a $25 million gift from the S.D. Bechtel, Jr. Foundation in support of efforts to create ten acres of new parkland in the Presidio.

The largest cash gift ever to a national park will cover more than half the estimated cost of the Tunnel Top Parkland — a bluff to be created above the new Presidio Parkway, allowing for an unbroken landscape leading from Crissy Field to the Main Post of the former military base, which now is part of the Golden Gate National Recreation Area. The gift also will be used to fund the expansion of indoor and outdoor facilities for youth programs at the Crissy Field Center.

The conservancy previously led fundraising and planning efforts for the hundred-acre restoration of Crissy Field and a network of trails and overlooks within the 1,491-acre Presidio — both of which were catalyzed by eight-figure grants from the Evelyn & Walter Haas Jr. Fund and completed with donations from other private donors. That is likely to be the fundraising strategy for Tunnel Top Parkland as well, the San Francisco Chronicle reports. "This gets us more than halfway there," said Greg Moore, the conservancy's executive director. "All these projects have major donors, but also grassroots people who care about parks."