Yellow caution tape marks the start of the Montour Trail at milepost zero on Montour Run Road in Moon, with another roll of tape stretched across the North Star Road trail head in Findlay.

This 9.5-mile section, the busiest and one of the oldest along the 30-mile trail, will be closed until further notice, Montour Trail Council President Dennis Pfeiffer said Monday.

Spaced in between those two signposts is a stew of mud, rocks, tree limbs and wood chards, as several sections of the trail were washed away into the adjoining Montour Run during Friday's record rainfall and flooding.

"The worst sections are starting at mile zero. Not only is the guardrail there washed out, but [H. Snyder Steel Corp.] is washed out," Pfeiffer said.

"It looks like a moonscape down there, with the road gone, the trail gone. These huge rocks are what's left."

The flood's most immediate effect is that the starting point of Saturday's Tour the Montour bike ride will be moved south to the Boggs trail head at mile 11.4 in Findlay. Starting times for the multidistance event remain as scheduled, but lengths will be shortened and relocated.

The family-ride fund raiser was supposed to start at mile zero and extend to mile 22; instead, it will start around mile 11 and the longest ride will extend to around mile 28 in Hendersonville. For more details, visit the trail Web site at www.montourtrail.org or call 412-257-3011.

Meanwhile, the flood has closed the access road that leads to the Snyder scrap yard, which Pfeiffer said has always been a good neighbor.

Now, the trail gets to return the favor since trucks will have to cut along part of the trail in order to get to the yard at 100 Montour Run Road.

On a deceivingly crisp and sunny Sunday, Pfeiffer walked the trail from mile zero to mile 5.9 at Cliff Mine Road in North Fayette. He didn't see as much mud as he had imagined and luckily, none of the six bridges were structurally damaged.

Still, the flood damage was extensive.

Aside from the mile zero trail head, the other sections hardest hit are near mile 1.4 at Hassam Road, just past the Moon water plant, and mile 3.1 at Old Beaver Grade Road in Moon.

Near Hassam Road and the Sportsmen's Club firing range, parts of the trail on both sides of a bridge have crumpled into the creek, leaving 5-to-6 foot craters.

Near Old Beaver Grade Road, he saw a stack of 20-foot wooden beams lying across the trail, having floated there from a nearby work site. The foot-thick beams were meant to be cribbing, or a foundation, for construction cranes.

"The stream just took over the trail," Pfeiffer said, "and took all the base. ...You can walk along the grass and there's 5-foot drops in certain places.

"We're going to need lots and lots of material to build the trail back up," he added.

How long it takes to rebuild the trail is anybody's guess, though Montour Trail leaders are optimistic.

There's plenty of volunteers who can pitch in, Pfeiffer said, once grants can be secured to pay for the material needed to rebuild the base and surface -- fist-sized rocks and pressed limestone that don't come cheap.

Earlier this year, Pfeiffer said a 600-foot section in Findlay was built and it took 66 tons at $14.50 a ton.

Trail leaders hope to get a better idea of repair costs later this week after meeting with their engineer, Dave Wright.

If there was any silver lining to be found, it might be that the flood didn't hit the region one weekend earlier. If it had, it might have wiped out the IKEA Montour Trail Half Marathon and 5K Race, one of the council's largest fund-raisers of the year.

The Montour Trail is in its 15th year and currently has 30 miles of continuous hike/bike surface open to the public in Coraopolis, Moon, Robinson, North Fayette and Findlay in the western suburbs extending into Cecil and other parts of Washington County.