River town rising

To stand on the glass deck of the new Sundial Bridge in Redding, California, is to feel suspended between heaven and earth. With the Sacramento River rushing beneath your feet and the bridge's gleaming white mast spiking more than 200 feet skyward, you could almost be floating on the mellow, cottonwood-scented evening breeze.

Soaring, yet intimate ― the $23.5 million span that opened on the Fourth of July is for people, not cars ― the Sundial is destined to become California's second-most-recognized bridge. But the 710-foot suspension bridge is more than an audacious architectural statement: It's the final turn in Redding's slow reorientation toward the Sacramento River.

Related• Riverfront parks and trails• Weekend in Redding

It wasn't all that long ago that the Sac, as locals call their river, was seen as barely accessible ― a resource valued mostly for electrical generation, irrigation, and gravel. Now it's the centerpiece of a 20-mile riverside trail system, a museum complex, and, by next May, an arboretum. People are birding, hiking, and cycling here, and anglers are pulling huge rainbow trout out of the river's restored fishery. The new Sundial Bridge brings it all together.

Redding is no longer just another place to gas up along Interstate 5. And with days cooling, summer crowds thinning, and the fishing picking up, September is a great month to take in all that the city and the river have to offer.

Return to the river

Like many older Western towns, as it grew, Redding pretty much took the river it was built on for granted. I-5 was routed so far east that many retailers, malls, and motels followed the traffic, leaving the old downtown core to wither. The river was mostly ignored.

Renewed appreciation for the Sac began in 1991, when a coalition of three museums and an arboretum proposed turning an abandoned gravel quarry and other riverfront land into a 300-acre cultural center ― Turtle Bay Exploration Park. The Redding-based nonprofit McConnell Foundation, which ultimately funded much of the $83 million project, saw this as an opportunity to shift Redding's center of gravity back toward downtown.

And when discussion of a bridge to connect the park's two halves began, it was the foundation that posed the critical question: What if the span were not just a pedestrian bridge but also an icon, a landmark ― a symbol of the cultural heart of Redding?

More than just a bridge

In spite of a globe-spanning resume that included some three dozen bridges among projects in 17 countries, Santiago Calatrava had never built a bridge in the U.S. Part architect, part engineer, and part artist, the 54-year-old Spaniard turned out to be the perfect designer.

The engineering challenges were daunting. The bridge would have to span critical salmon spawning grounds without putting any footings in the river below. Calatrava's solution: Build a single pylon tall enough to cantilever a full 80 percent of the bridge from the north bank of the river. Nonskid glass decking lets cloud-soft light fall on the river below. The bridge also has to handle enormous variations in flow--the river can go from 4,000 cubic feet per second in the fall to 80,000 cfs at flood stage.

Simple and elegant, like a harp rocked back on its frame, the bridge and its spire had an unexpected surprise for its designer. "After environmental assessments showed the ideal place for construction, we saw that the bridge would run exactly north-south," Calatrava says. "This orientation relates the bridge to the cosmos, just as a sundial does. When the shadow cast by the mast passes over the plaza on the north side of the river, it marks off the hours."