More than 1,000 people on bicycles gathered in a parking lot at Sandcastle Waterpark in West Homestead this morning to celebrate the completion of the last mile of the Great Allegheny Passage. There were at least that many hugs and pats on the back.

"Wow," said Linda McKenna Boxx, to an ovation when she took the stage. "To look out at all of you here today. If we had known that it would take 35 years and $80 million, I dont know if we'd have had the heart to do this."

Ms. Boxx, the president of the board of the Allegheny Trail Alliance, was described by Jack Paulik, the alliance's project manager, as "the mastermind" in putting together all the pieces.

But she called out the names of a dozen people who gathered in a line in front of the stage, each of them having taken the lead in advocating for a connecting segment. "This is the human chain of the Great Allegheny passage," she said as they linked arms.

After the ceremony, the crowd rode single-file, slowly, 6.5 miles to the Point to celebrate again. Among the riders were Rep. Mike Doyle, who spoke in a bicycle helmet, and former Pittsburgh Mayor Tom Murphy, who wore fingerless biking gloves.

"We will ride slowly, to savor the moment," said Seth Gernot, who led the procession with an American flag given by U.S. Sen. Bob Casey before Mr. Gernot and a dozen riders left yesterday from Washington, D.C. to arrive at Sandcastle in time for the ceremony.

The trail from Pittsburgh to Washington, D.C. is 328.5 miles.

The last nine miles entailed a feat of engineering for which Mr. Paulik recognized several firms whose engineers brought the project in at $13 million.

"It required three new bridges, a tunnel and a great wall" near Keystone Metals, which donated a segment of its land, as did Sandcastle, he said. "These were not considered in the $13 million budget, but the engineers created a remarkable leg of trail at the original budget."

First Published: June 15, 2013, 7:00 p.m.