Nearly two decades after the National Park Service proposed a 60-mile bike and pedestrian trail along a part of the Delaware River, the dusty plans are picking up steam.

A colorful map of the Delaware River Heritage Trail depicts a loop connecting 24 towns, mostly on the riverfront, in southern New Jersey and Southeastern Pennsylvania. The Calhoun Street Bridge in Trenton and the Tacony-Palmyra Bridge would complete the circle.

So far, studies have been commissioned on both sides of the river, and signs have been planted in areas where sidewalks, roads, and paths have been linked to create several fragments of the trail.

In June, the Heritage Trail got a bigger boost when Burlington County received a $2.3 million federal grant to create a five-mile segment of the loop through a few towns and villages and then Trenton was allocated $300,000 in federal funding to link its waterfront trails with new bicycling trails in the city's downtown.

"The key mission is to link them all together. . . . There's still significant work to do in both states," said Shawn Megill Legendre, a senior research analyst with the Delaware Valley Regional Planning Commission. The DVRPC helped with the grants and is working with the Delaware River Greenway Partnership and other groups to get the Heritage Trail built.

When the National Park Service unveiled the proposal for the Heritage Trail in 1998, some planners said that it could become a part of an "urban Appalachian Trail" that one day would go from Maine to Florida, providing bicyclists with a seamless East Coast path.

"We are all working on this together," said Legendre, describing the trail creation as filling in gaps and patching segments together.

The Heritage Trail would start in Trenton, travel south through Burlington County and past several historical sights, and then cross over the Tacony-Palmyra Bridge. Then, it would head north, traveling through Philadelphia's Tacony neighborhood, into Bucks County and then to Morrisville, where it would continue over the Calhoun Street Bridge.

"From a recreational standpoint, people are interested in taking longer hikes and bike rides," said Matt Johnson, the coordinator of parks development in Burlington County. ". . . It also helps with the health and wellness of people in the communities."

More than a decade ago, a series of existing bike trails, sidewalks, and paths through the woods were linked to connect Trenton with Bordentown City, and that became the first segment of the Heritage Trail on the New Jersey side. Planners had persuaded New Jersey Transit to include a pedestrian path along the rail line when it was extended into Trenton, to fill in one of the Heritage Trail gaps.

Then, in 2013, Burlington County extended that part of the trail southward, creating a 2.3-mile segment that linked Bordentown's beach on the Crosswicks Creek to its historic downtown and then into Bordentown Township and Fieldsboro, using a $1.5 million federal grant.

The new $2.3 million grant from the Transportation Alternatives Program will allow the county to continue the loop five more miles, from Fieldsboro to the site of the historic Roebling Steel Mill in Florence. Johnson said the loop will include an asphalt path that will traverse wooded sections of the county's Crystal Lake Park in Mansfield Township and then go through the historic Roebling Museum complex.

Construction is expected to begin as soon as next summer and could be completed by 2018, Johnson said.

Bordentown Mayor Joseph Malone said the loop had sparked new interest in the area, especially on the gravel beach next to the Crosswicks Creek. Picnic tables and gazebos were erected along with special lighting in that area. A kiosk contains information about the trail and the historical sights people can view along the way.

"For us it's become a nice asset," he said. ". . . This is what people want."

James Whittier Parker runs a production studio adjacent to the part of the trail in Bordentown that runs along a part of the light rail line. He said he sees "several hundred bicyclists, joggers, and pedestrians on the trail on nice days and on weekends."

Parker said the roughly four-mile segment goes from a sidewalk near the Bordentown Yacht Club, over a wooden trestle bridge, through a wooded area, and along the creek and river. "You can ride or walk all the way up to the Waterfront Park in Trenton," he said.

Often, people stop in to ask about the trail, he said. "It's a way to enjoy nature and be off the beaten track," he said.

On the Pennsylvania side, the trail mostly follows the existing D&L Canal Trail and is maintained by the state, Legendre said. But development and new roads have created a few interruptions that need to be addressed before the Heritage Trail can come together.

For example, he said, the construction of Route 13 in Bucks County bisected parts of the trail. When the highway was redone a few years ago, he said, a tunnel was built beneath it to accommodate the Heritage Trail users.

856-779-3224 @JanHefler