A proposal to create an elaborate park system running the length of four rivers in Allegheny County and costing almost $100 million has cleared its first hurdle.

A County Council special committee on riverfronts endorsed the concept during a meeting yesterday. The action paves the way for the full council to vote on the proposal at its meeting in two weeks.

The ordinance council will consider would authorize the county to map the boundaries and dimensions of the park and allow it to acquire land for the endeavor, if the purchases are approved by council and the chief executive.

As envisioned by the architects of the plan, county Councilmen Dave Fawcett and James Burn Jr., the park would run along one shore of the Allegheny, Monongahela, Ohio and Youghiogheny rivers and stretch some 75 to 100 miles.

The idea is not only to connect existing trails but to provide other amenities such as playgrounds, tennis courts, cross-country skiing, mountain biking, picnic areas, and rowing facilities. Mr. Burn, a Democrat, and Mr. Fawcett, a Republican, are hoping the plan will help spur economic development in many of the old steel and industrial towns dotting the rivers.

"We're proposing it purely and simply as a matter of economic development," Mr. Fawcett said. "If it's done right, it pays off. It's a good investment."

Mr. Fawcett told the committee yesterday that getting the proposal approved has taken on more urgency now that he has learned of plans by a developer to build self-storage facilities on a key Allegheny River parcel near Verona.

He said the property owner is willing to discuss the sale of the land, but that the county now has no authority to acquire it. The ordinance would change that.

"It makes the whole thing very urgent," he said. "I think this is a key moment because it forces us as a county to make a decision on what we want our riverfronts to look like."

Mr. Fawcett and Mr. Burn are hoping to tap into three sources to fund the proposal -- the Allegheny Regional Asset District, which now provides money for city and county parks; the state; and foundations and philanthropic organizations.

Given that the city and county already are building trails along the riverfronts, the countywide park is an idea county Chief Executive Dan Onorato is willing to consider, spokesman Kevin Evanto said.

"Obviously they would complement one another so he's willing to consider the idea and take a look at it," he said.

But he added part of that involves finding out just how the plan would be funded.

If the ordinance is approved, Mr. Fawcett believes it will put the county in a position to attract funding and to talk to property owners along the river about acquiring real estate, particularly railroads, which have been reluctant to part with land in the past.