Congress has passed and sent to the president a bill that would establish the Lewis and Clark National Historical Park (search) in Oregon and Washington state.

The bill would expand and rename Fort Clatsop National Memorial (search) in Oregon in honor of explorers Meriwether Lewis and William Clark. It also would add three sites along the lower Columbia River, bringing the park for the first time into Washington state.

The Bush administration proposed the federal park in February, calling it a fitting way to mark the bicentennial of the pair's expedition seeking a northwest passage to the Pacific Ocean. The Senate gave the measure final congressional approval Sunday night.

While the Lewis and Clark-led Corps of Discovery (search) spent the winter of 1805-06 in Fort Clatsop, the expedition traveled widely over the region, making a two-state park appropriate, said Interior Secretary Gale Norton.

The park plan follows approval of a law two years ago to expand the Fort Clatsop memorial from 130 to 1,500 acres. The three new sites would add another 560 acres to the park.

"From minting new coins to printing commemorative stamps, Americans have already started celebrating the journey of Lewis and Clark," Sen. Gordon Smith, R-Ore, said in a prepared statement. "This bill will help us provide a fitting tribute to the explorers who opened up our nation."

The sites to be added to the park include the Station Camp (search) site near McGowan, Wash., where Lewis and Clark camped before returning east in 1806, as well as the Megler Rest Area (search) and Cape Disappointment State Park (search), formerly known as Fort Canby State Park.