SAN FRANCISCO (KGO) -- Every morning, thousands of drivers pour through the tunnels of San Francisco's Doyle Drive without realizing they're flying over what will soon be one of the Bay Area's most spectacular landscapes."We're standing under Doyle Drive, rebuilt Doyle Drive, at an area we call Quartermaster Reach," says Michael Boland of the Presidio Trust.Boland has been with the Trust since the original transformation of nearby Crissy Field from a semi-industrial stretch of dirt and asphalt to a shoreline mecca.When we restored Crissy Field, the marsh at Crissy Field, I mean within days there were fish in the marsh, there were birds using the marsh," Boland remembers.Now, Boland and a team assembled by the Presidio Trust is about to stitch a new scene into this stunning tapestry -- connecting a network of hidden creeks, watersheds, and natural wetlands that have buried for more than a century.Aerial views show Quartermaster Reach sandwiched between the Presidio's interior and the Crissy Field shoreline. While mostly flat dirt after the completion of the new Doyle Drive, planners now envision a ribbon of spring fed marsh and wetlands, ultimately spilling into the bay."This is the spot where fresh water from Tennessee Hollow comes into the salt water of the bay. And the really nice thing is the public will be able to walk through it on a boardwalk and trail," Boland adds.To make that vision happen, crews will be excavating acres of watershed and routing it underneath at least one busy road to reach the bay.Project manager Genevieve Bantle says the job is complicated and extremely delicate."So we have a geotechnical engineer, civil engineer, landscape architect, hydrologist, geomorphologist," she says rattling off the list of dedicated experts.Nearby, crews are already adding new landscaping to the top of the Doyle Drive tunnels. And in the upcoming months, work will begin on Quartermaster Reach. Its a transformation that will ultimately allow visitors to walk from the edge of Pacific Heights to the Crissy Field shoreline along a watershed that looks much like it did a century ago."You'll see a marsh with woodland all around it, buildings will just peek out of the top. It's like being in the high Sierra and going to the bay, but it's just in the Presidio," says Boland.