We’re walking the Valley’s river, a combination sewer system and wildlife habitat that carries 150 million gallons of storm water and urban runoff through the wetlands and into Lake Mead every day. Hypodermic needles are tossed trailside; dirty diapers are thrown over a fence from an apartment complex; a plastic bag of trash rides atop the current. Wildlife roams the rich habitat, and discarded water bottles form island communities on the banks when the water ebbs.

This is the Flamingo Arroyo Trail, a beautiful then bleak, filthy then clean, series of changing landscapes that hug the Flamingo Wash, one of eight water sources that feed into the Las Vegas Wash, then head to Lake Mead.

There are a million stories along the trail. Just west of U.S. 95, where a lean man paces slowly under the freeway with his belongings crammed into a shopping cart, we near a forested swatch behind a black, steel gate. A clearing shows a paint-chipped, wooden two-story structure that housed prostitutes who crossed the wash in the 1950s to service men at Roxie’s brothel, a story detailed in The Green Felt Jungle. A hummingbird feeder hangs from the porch of a broken-down home with a newish car parked out front. The owner, we’re told, has lived there most of his life.

At Miracle Mile Mobile Home Park, the wash is a concrete flood channel that slices through the open neighborhood. Here, the urban river is personal. In 1999, we watched trailers at Miracle Mile fall into the wash and get carried away during the 100 Year Flood. Now, it’s cemented in, stabilized.

The sun is setting as residents come home from work, stop and talk to each other. Kids play soccer in a narrow street. A father and son ride their bikes along the path. A young boy and his grandmother lean over the guardrail to throw rocks into the water, as if it were a river in any town. Farther upstream, a bruised woman asks if we’ve seen her fiancé on our journey. We should have passed him along the way, she says.

These days, officials are pushing for more of these concrete channels to ferry the water quickly to Lake Mead, which brings return flow credits to Southern Nevada. Residents living along the wash oppose the idea, which would turn it into a concrete bed resembling the Los Angeles River. During a meeting to discuss artists Buster Simpson, Barbara Grygutis and Kevin Berry enhancing the wash’s trailheads, the main concern was not over their project, but the possible cementing of the wetlands.

Volunteers clean up the area. Graffiti is covered. Revegetation efforts on 181 acres help clean contaminated water and offer a wildlife habitat to hundreds of species of fish, plants and animals.

Just north of Vegas Valley Drive, where the concrete bed turns into a wildlife creek (greenery, birds and little eddies around grassy islands), we see the ghosts and remnants that linger. Riprap from imploded hotels has been placed in the stream to bolster its shores, and the still-standing Stratosphere, which would likely provide an endless supply of riprap, towers in the distance. It’s perfectly scenic. A bird sings, a brook babbles, a plane flies overhead and nervous quail cross our path. We watch a teenager cut across the rocks in the wash and hop onto the stucco wall leading into his neighborhood. He cuts through when the water runs low; other times he travels through the golf course. Either way, it’s a series of climbing fences and walls to get home.

The nearby Sloan trailhead is landscaped and includes shade shelters designed by Simpson, Grygutis and Berry. As with the enhancements at the Pecos/McLeod Trailhead, it seems to promise a scenic journey. For some residents along the wash, it delivers.

The paved pathway is part of a large network of trails developed to offer recreation and alternative transportation routes in the Valley. Construction began in 2004, and original plans called for the Flamingo trail to extend from the Wetlands Park to Maryland Parkway, but there is no funding available to take it west of the Pecos/McLeod Trailhead just south of Desert Inn.

The trail takes us along the Flamingo Wash, then merges with the Las Vegas Wash, a 12-mile wash that has been here longer than any of us. The natural drainage channel dates back millions of years and changed dramatically in the 20th century, when Valley growth sent more water rushing through the bed, causing massive erosion and dumping sediment into Lake Mead. Then came the environmental studies and the findings of rocket fuel, which had entered the wash and Lake Mead through contaminated groundwater.

Like any river, Vegas’ washes serve as a lens into the economic diversity from neighborhood to neighborhood. Occasionally, someone will fish their waters, and a pole, along with grocery carts, have been left behind.

Where the Sloan trailhead dead-ends at the Desert Rose Golf Course, we climb the fence and walk the green at the intersection of the Flamingo and Las Vegas washes. It’s scenic and lush, the wash becoming a narrow canal in the greenery. Further on, we pick at the golf balls wedged into the ground from failed swings, then move along, eyeing nearby homes and dogs. A golfer, posting his thoughts of the public course on worldgolf.com, called the wash a sewer running through the greens. A harsh statement, but not exactly wrong. The wash means something different to everyone.