Washington ? Congress revived legislation Wednesday to create a geologic trail that would trace the route of a series of catastrophic Ice Age floods that inundated much of the Pacific Northwest, leaving permanent scars across the region.

Visitors could drive the 600-mile trail stopping at interpretive centers and roadside pullouts with signs and markers to learn about the floods that were unleashed when an ice dam in what’s now Montana collapsed, draining a lake the combined size of Lake Erie and Lake Ontario in two days. The trail would cost $8 million to $12 million to create, and the National Park Service would oversee it.

The Senate Energy and Natural Resources Committee approved the measure Wednesday.

“The size and scope of what happened here is hard to fathom,” Sen. Maria Cantwell, D-Wash., the prime sponsor of the bill, said of the floods. “This is one of the most unique events in the geologic history of the Earth. We usually see things like this on other planets.”

Similar legislation cleared the full Senate last year but died when the session ended before differences with the version that the House passed could be resolved. Cantwell said she expected the measure to pass Congress this year.

The floods 13,000 to 18,000 years ago redistributed more than 50 cubic miles of earth and rock, leaving in their wake coulees, buttes, boulder fields, lakes, ridges and gravel bars that remain today. The floods provided much of the fertile soil that’s found in Oregon’s Willamette Valley and left behind the 189-foot Palouse Falls in eastern Washington along with Dry Falls, which has a rim 10 times that of Niagara Falls.