The official ribbon-cutting is at 1 p.m. "The day's theme is 'You envision it, we built it,'" said Marilyn Sandifur, spokeswoman for the port.

The event is designed to introduce the park and educate the public about its maritime, historical and environmental connections, Sandifur said.

Councilmember Nancy Nadel, Port Commission President Patricia Scates and park district board President Doug Siden will be on hand to launch the festivities.

Because of the environmentally sensitive nature of the new park, the public is asked to leave pets at home. Using public transit is encouraged, and AC Transit bus No. 13 runs every half-hour from West Oakland BART. There will be free bicycle valet parking for those coming by bike. Take Seventh Street (from the BART station), 1.10 miles to the park.

Both the port and part district will have educational displays about the making of the park and community input in the project.

It is built on the site of the former Oakland Naval Supply Depot, a 500-plus acre wartime facility with dozens of warehouses and a combined floor area of more than 7 million square feet, said port environmental planner Celia McCarthy.

"The depot was a supply center for the Navy's Pacific Fleet from World War II until 1998, when it was closed and the property was transferred to the port," she said.

According to library history files, the Navy depot played a significant role in the effort to transport military supplies to the Pacific Theater and was a primary reason the United States was able to "out-produce and out-supply its opponents."

Civilian and military workers processed and shipped a wide variety of cargo, including clothing, food, medicine, fuel and medical equipment.

"Research has revealed that from 1945 until 1970, it was the world's largest supply base, and for over two decades was the East Bay's largest employer," McCarthy said.

"During the war, military bases, including the shipyards, operated around the clock, every day of the week, creating a huge demand for defense labor."

Some 1.5 million people came to California to work in war-related jobs. Almost one-third of those migrants came to the East Bay.

Of the 345,000 laborers coming to California in 1944, close to 20 percent, many of them African Americans, came from such Southern states as Louisiana, Arkansas and Texas.

Most of the base structures were warehouses and offices, but the depot also had its own fire and police stations, a library, post office, bank, cafeteria, chapel, bowling alley, movie theater, lounges, barracks and houses for officers and their families. "It was its own self-contained city, with 42 miles of train tracks and 26 miles of paved roadway," McCarthy said.

Navy Cmdr. Lin Loring said: "Without the Oakland Depot, you probably wouldn't have won the war ... you had a huge fleet out there to supply, and it all came out through Oakland."

When the Navy began construction of facilities in 1942, the land was tidal wetlands, mostly underwater at high tide. Naval engineers used materials from dredging operations as well as from the Oakland hills to fill in the wetland site, a process then considered "reclamation" of submerged lands, an action that took place at many bayshore locations during that era.

"Today we know that unregulated fill can destroy wildlife habitat essential for the health of the Bay," McCarthy said.

Ill-advised fill has greatly reduced the Bay's wetland habitats. The new Middle Harbor shoreline is one of several planned or recently completed restoration projects expected to increase wetland habitats by more than 60,000 acres.

Mounted historical displays throughout the park tell the story of rebuilding the habitat, which includes a beach, a spawning ground for shallow-water fish and stop-over for migratory birds.

The crescent-shaped park encompasses remnants of the historic 1910 Western Pacific Mole, which once extended nearly two miles into deep water, and where ferries plowed from Oakland to the San Francisco shore during the era before bridges spanned the Bay.

"Visitors can walk out along a pathway known as the John Alexander Promenade (named for one of the civilian depot workers and a longtime West Oakland community leader) to a lookout tower (dedicated to environmentalist Chappell Hayes) with amazing views of the Bay waters, bridge and San Francisco skyline," McCarthy said.

There is a footprint of a 190,000-square-foot warehouses that was once part of the depot. "Look for a 'ghost structure' with wall markers, zigzag walls and changes in the pavement," McCarthy said. "It gives a suggestion of the vanished building's mammoth size and roof line.

"Tons of crushed concrete from the demolition were used as base rock for the new marine terminals. Altogether, six of the historic Navy buildings were deconstructed and more than 2,000 tons of timbers, doors and windows were salvaged.

"We were also able to salvage sections of a historic masonry jetty, known as a training wall, set out along the estuary's shipping channel 130 years ago by the U.S. Army Corps of Engineers. The training wall jetties deepened the channel so ocean-going vessels could sail up the Estuary, a key development in the creation of Oakland's port."

Volunteers who want to help with Saturday's celebration may call 627-1135. The general information number is 627-1200. "Folks can log on to www.KFRC.com, our media sponsor to find out more about the musical entertainment lineup," Sandifur said.

Limited seating is still available for the Sept. 23 Oakland Historic Houses bus tour. Contact the Pardee Home Museum, 444-2187, to make a reservation.