State officials have a clear view of how they'd like to restore Kinzua Bridge State Park in McKean County. It involves a clear view -- through a glass-bottomed overlook -- down into the bottom of the gorge.

"It would be an octagon out at the end with a see-through floor," said Jason Zimmerman, manager of the park complex. "If you go all the way out to the end of what's left, it's about a 220, 240-foot drop."

"What's left" are the six southern towers that at one time supported the historic half-mile railroad bridge 301 feet above the valley floor. Built in 1882, then rebuilt in 1900 to handle heavier trains, the Kinzua Bridge was once the highest railroad bridge in the world. A popular 392-acre park around the bridge opened in 1970.

But after the supporting towers began to show serious deterioration, the bridge -- listed in the National Register of Historic Civil Engineering Landmarks -- was closed to traffic in 2002. An extensive restoration project was under way on July 21, 2003, when at least two tornadoes swept through the park, crumbling 11 of the 20 bridge towers, snapping thousands of trees and collapsing a park maintenance building.

The state Department of Conservation and Natural Resources committed $5 million to restore what remains of the historic landmark, including the six southern viaduct towers. The project also could include a visitors' center, parking lots, and an overlook on the towers that would allow visitors to follow paved, safety-railed walkways from park grounds to the end of the structure. There they could look across the Kinzua Valley at three other towers left standing or down to the twisted remains of the bridge scattered far below.

"We can never repair what nature tore apart, but we are committed to using the viaduct's remains and park resources as learning tools for those who visit," said John W. Norbeck, director of DCNR's Bureau of State Parks. "Conceptual overlook plans call for installation of a glass deck at the end that should prove exciting for the not-so-faint of heart."

The project was awarded in January, but it had to be pulled back because the low bid did not meet requirements. Mr. Norbeck called the "temporary setback" unfortunate and said the project is being put out to bid again in April.

Mr. Zimmerman said the toppled viaducts are staying on the valley floor "as an interpretive piece" to show the magnitude of the bridge and the power of the storm that brought them down.