When the dangerously deteriorated Betzwood Bridge was demolished in 1995, the only overwater bike path between the Schuylkill River Trail and Valley Forge National Historical Park disappeared with it. To placate irate cyclists, PennDot bolted a fenced boardwalk four feet wide to the eastbound shoulder of the neighboring Route 422 bridge.

The bellyaching got worse.

Amanda Lozinak, 24, of Spring City, often leads women's rides on the Schuylkill River Trail with her Bike Chester County advocacy group. "Every time we ride [the bridge] into Valley Forge, it feels so unsafe," she said. "Some of the nails have come out. Some of the wood is loose. When you're on that bridge, I would not suggest looking down."

Michael Broennle, 74, a lifelong bicyclist from East Goshen and a founder of Friends of the Chester Valley Trail, described the unnerving passage in which "two bicyclists coming from opposite directions cannot ride past each other. You have the noise of cars whizzing along right next to you at 60 miles per hour."

But a sweet ride is just ahead for Broennle and Lozinac. This summer, PennDot's new Sullivan's Bridge - a $9.2 million, 14-foot-wide, pedestrian/cyclist river crossing built in the footprint of the Betzwood - will open, banishing the Route 422 boardwalk bridge forever.

Named for Major Gen. John Sullivan, who served under Washington at Valley Forge, Sullivan's Bridge is the 2016 diva of the Circuit Trails, a burgeoning regional network of foot-power pathways to Mother Nature.

Funded largely by government agencies such as PennDot and by private grants from the William Penn Foundation and others, the Circuit comprises more than 300 miles of trails in nine Pennsylvania and New Jersey counties. The goal: 750 miles.

Permanently installed counters recorded more than 1.2 million pedestrians and bicyclists on 11 major regional trails last year, including 240,182 on the Chester Valley Trail, 208,180 on the Schuylkill River Trail in Phoenixville, and 114,619 on the Cynwyd Heritage Trail in Lower Merion Township.

The Circuit's summer expansion includes the new Pencoyd Trail and the bike path outrigger on the rehabbed Pencoyd Bridge between Manayunk and Lower Merion. The $5 million project was privately funded for public use by O'Neill Properties Group in exchange for township permission to build 569 riverside apartments in Bala Cynwyd on the old Connelly Container site.

Opening in the fall will be a federally funded, $6.5 million, 2.8-mile stretch of the planned 6.7-mile Chester Creek Trail. Though the first part to be built, it is what will be the trail's midsection, from the former SEPTA Regional Rail Wawa station to the 17th-century Caleb Pusey House in Upland Borough. The 10-foot-wide, paved path sits atop the former rail bed of the Pennsylvania Railroad's 19th-century Chester Creek branch line in Delaware County.

"It runs along Chester Creek, mostly in Middletown Township," said John Paulson, who lives near the trail and is longtime treasurer of the Friends of Chester Creek Branch Rail Trail. "We beat the bushes up and down and sideways, and Middletown was the first township that said yes."

Walkers, joggers, bicyclists, roller-bladers, and "any self-propelled mode of transportation other than a horse" will be welcome, he said.

Paulson and his sweat-equity colleagues plan hands-on care of the trail. "I'll be cutting up trees that fall down there as long as I am able to work a chainsaw," he said.

Sixteen miles away, a similar can-do spirit infused the 30,000 volunteer hours spent turning a desolate dumping ground into the two-mile Cynwyd Heritage Trail in 2011.

Last fall, the $5.7 million rebuild of the Manayunk Bridge extended the trail from Lower Merion across the river to Manayunk.

The sparkplug for the Cynwyd Heritage Trail was Chris Leswing, Lower Merion's assistant director of building and planning, who spent 20 years helping Clark Park become a West Philadelphia community oasis before he moved to the suburbs. There, he said, he realized "Lower Merion had ball fields and green spaces with creeks, but no trails and no places people could gather for public events. I wanted to use open space to create civic space."

On Good Friday 2005, he hiked two miles along deserted SEPTA tracks from Cynwyd Station to the abandoned Manayunk Bridge, across the Schuylkill and into Manayunk, where he ate lunch, and then walked back.

"There were abandoned cars with bullet holes, mattresses, construction debris dumped along the tracks," he said. "It was a forgotten space, but as cool as you can imagine. It had this funkiness of overhead wires, industrial elements, and stone walls mostly overgrown. It had cliffs, elevations. It had really neat bones. You could see making spaces where people could gather. I said, 'Holy wow! This should be a trail!' "

Leswing can't recall how many Friday afternoons he spent hiking through his vision with Montgomery County players. "Anybody I could, I would drag out there," he said, laughing. "We'd always walk to Manayunk and have a beer, so on the way back, the trail project suddenly made more sense to them and they said, 'We've got to do this!' "

Leswing promoted his imagined trail at public meetings as Lower Merion's recreation and transportation future. At one, he said, "An older gentleman, very reserved, talking very slowly, got up and said, 'You want to build a trail in my backyard? You've heard of NIMBY? I'm a PIMBY - please build it in my backyard.' "

Montgomery County ponied up $1.7 million; the township and the state, a combined $1.8 million. Today, thousands enjoy Cynwyd Heritage Trail.

As for Sullivan's Bridge, it has a fervid following even before it opens. Michael Broennle, who has biked regional trails since 1973, said he looks forward to riding his recumbent trike from the Chester Valley Trail near his home to Valley Forge National Historical Park, over Sullivan's Bridge, to the Schuylkill River Trail.

"I was there for the Sullivan's Bridge groundbreaking in 2014," he said. "I'll be there for the opening this summer. I was the first trike to go across the new Manayunk Bridge when it opened in October. I rode over to the Cynwyd Heritage Trail. If it's about trails, it's easy to get me started and hard to get me to stop."