The prospect of the old Montour Railroad yard becoming a riverfront park and athletic center is great news for Moon and Robinson.

It is ... well, good news for Coraopolis.

"Short of getting commercial development on that site, this is the next best thing," Coraopolis Manager Tom Cellante said last week.

The $10 million to $15 million complex, announced by Allegheny County last week, will include 10 or 11 sports fields on 78 acres. Most will be large enough to accommodate sports such as soccer, rugby and lacrosse, and it's being touted as an ideal site for hosting tournaments and other large-scale events.

The plan also includes extending the Montour Trail biking, hiking and jogging path from Route 51 to the Coraopolis bridge.

Together, those factors promise a boost to Coraopolis' economy. The park site lies at the east end of town, and 40 of the 78 acres are within borough limits. Mr. Cellante said he could easily see shops and eateries springing up there to serve those using the fields and trail.

"I know people who use the trail a lot, and they complain that when they reach the end, there's not even a place to get a bottle of water," he said. "If it comes to fruition, it should hopefully spur some business."

But it falls short of "great" for one significant reason. Coraopolis is in dire need of the tax boost a large-scale commercial development would offer, and "that 40 acres was the only piece of land in town that could have been developed," Mr. Cellante said. Other vacant property in the 1.3-square-mile borough comes in one-lot chunks.

Despite efforts to attract major developers, however, the property had one great drawback: It would need to be built up about 7 feet to get out of the flood zone, and that was a potential $40 million job.

The park announcement also creates one other lost opportunity.

Local leaders for decades pushed the state Department of Transportation to build a ramp to let southbound Interstate 79 traffic reach Route 51. Over the last eight years or so, though, PennDOT has targeted its projects to help development; thus the only real chance to get a ramp would be to find a developer for the old rail yard.

Leaders in Moon and Robinson, both suburban townships with plenty of space and growth elsewhere, had no such hesitations on the project.

"I feel privileged that now we're going to have a county park on the riverfront, partly in Robinson," Robinson Commissioner Dan Tallon said.

"My personal opinion is that the rivers are an asset for all the community." When possible, he said, "they should be kept for special interests and recreation."

Moon Manager Greg Smith said that his community's strategic plan includes "a clear call for more park space," and noted that sports organizations are always looking for fields.

He also said that Moon has been acquiring property along Montour Run to ensure that the trail is going through natural terrain. The first portion of the extension will be in Moon before crossing into Coraopolis.

Mr. Tallon also said there will be good synergy between the park and Island Sports Complex, across the Coraopolis Bridge on Neville Island. There is also a hotel under construction on the island.

"I'm personally very excited," he said. "I think it's a great thing."