With its elegant stone arch supported by thick columns, the Rausch Gap Bridge began carrying trains across the swift Rausch Creek in 1854.

But time has caught up with the historic span, which was turned over to the state for recreational use in the mid-1940s. Stones from a lower section of the arch have tumbled into the water .

This month, the bridge, which served hikers on the Appalachian Trail and the Stony Valley Rail Trail in Lebanon County's Cold Spring Twp., was closed to all traffic. Hikers and horseback riders now have to carefully pick their way across the creek below.

"One more stone could be the tipping point" that causes the bridge to collapse, said Bruce Metz, a land-management supervisor for the Pennsylvania Game Commission, which owns the bridge that is part of the Appalachian Trail.

About 100 people used the bridge some summer weekends, said Brandy Watts, who has written about the Schuylkill & Susquehanna Railroad, which built the bridge.

The crumbling bridge and the uncertainty about where the money will come from to repair it underscore the larger issue: how to pay for aging infrastructure in the state's parks and game lands.

"We don't have the money to fix it," Game Commission spokesman Jerry Feaser said of the bridge.

Harrisburg-area commuters have only to look at the Walnut Street Bridge over the Susquehanna River to see the problem. "Old Shakey" has been missing the section that connected City Island and the West Shore since it collapsed during the flooding of January 1996.

"How do you justify spending $12 million or more when you already have a bridge providing pedestrian access to City Island and Harrisburg?" asked Greg Penny, a spokesman for the Pennsylvania Department of Transportation.

State officials said they are making headway on a backlog of repair and replacement projects in state parks, forests and game lands, thanks in no small part to voters' approval in 2005 of so-called "Growing Greener II" bonds.