On a broiling September afternoon, UCLA associate professor of English Allison Carruth carries a butterfly net as she winds her way through the crowd gathered at Glendale’s Marsh Park alongside the Los Angeles River. Dressed in cherry-red sneakers, jeans and a glittering pink scarf, she’s bringing the net to Natural History Museum of Los Angeles County staffers as they prepare a presentation about the wild things that call the river home.

“The scientists do insect capture to show the range of insects at the park,” Carruth explains a few days later. “In the evening, they used this electrical frequency mechanism to capture all the sounds that bats make, which are undetectable to our ears. It shows people that these bats are all around us at the river, even though we can’t see them.”

“Insect wrangler” is just one of several roles embraced by Carruth to help launch the Play the LA River program at Marsh Park II, in the northeast Los Angeles community of Elysian Valley known as Frogtown. Created by the arts collective Project 51, the program centers on a new guide to river sites that is formatted as oversized playing cards and designed to popularize the 51-mile waterway as a place to have fun, relax and commune with nature.

To kick off the 51-week initiative, Carruth and her colleagues distribute decks of the informational cards amid a whirl of arts, crafts and “citizen science” activities. Blue and red balloons waft through the sky, embedded with cameras that capture aerial photographs of the landscape. “It’s like the original drone,” explains Los Angeles Natural History Museum educator Lila Higgins.

Nearby, Mountains Recreation & Conservation Authority outdoor leader Caitlin Tozer spins a Wheel of Fortune–style game board illustrated with pictures of the double-crested cormorant, cinnamon teal, red-tailed hawk, green heron and American coot. Visitors who try to guess how these local birds of prey grab their food get to pluck a gummy worm with a fork or straw, chopsticks or tongs to emulate the birds’ mode of attack.

Beneath the shade of the Marsh Park pavilion, three Poetry Society of Los Angeles members tap away at old-fashioned typewriters to produce water-themed verse. Stephanie Cheng Smith created tiny motors that make chirping sounds for her Crickets installation of experimental music, part of a series of performances curated by the wulf.

And Down by the Los Angeles River author Joe Linton mans the world’s tiniest “reading room.” Hovering over a two-foot-square bench, he rattles off a list of nonnative fish that make good eating — rainbow trout and other native species that vanished decades ago — and explains why the river runs through cement-clad channels. “There were two big floods in 1934 and 1938, so that’s why they started to concrete the river,” Linton says. “Concreting really kicked into gear after World War II through 1960 at a total cost of $5 billion in today’s dollars.”

The legacy of that decades-long flood-control effort shows up a few feet from the Marsh Park festivities, where a shallow stretch of the Los Angeles River flows. Lush trees and bushes overgrow one bank. The other side of the river, stripped bare, reveals a man-made shoreline constructed of gray slabs of cement.

Far from the picturesque river archetype associated with natural “soft bed” waterways, the Los Angeles River’s hard-edged contours compelled a radical shift of perspective for Carruth when she moved to UCLA two years ago. “I grew up in Colorado and spent a lot of time hiking in the Rocky Mountains, backpacking around rivers and the high mountain lakes that feed them,” she says. “When I first got involved with Project 51, I found myself thinking a lot about the way I experienced rivers as a child. My whole memory and understanding of ‘river’ was completely different, because I grew up around the ecosystem of the wilderness, not of the city.”

Carruth’s work with Play the LA River reflects a fascination with urban ecology that has informed her writings, including a work-in-progress titled Radical Gardens, Digital Times. An affiliated faculty member in the UCLA Institute of the Environment and Sustainability, she also addresses urban planning issues in her interdisciplinary Introduction to Environmental Humanities class. “I’ve been very excited to teach courses that get students seeing the city through an ecological lens,” Carruth says.

Noting that Los Angeles ranks far behind most American cities in the availability of public green space, she explains, “The class deals with the park-poor history of L.A., and we explore maps and schematics that document our lack of green space in any conventional sense, compared to cities like San Francisco, Chicago or New York. For Project 51, one of the huge opportunities is to realize that this river runs through 18 cities and offers a unique opportunity to enhance green space and access to parks for neighborhoods all across the L.A. basin.”

Carruth first became acquainted with the Los Angeles River’s off-kilter charms at the behest of Project 51 convener and co-founder Jenny Price. A research scholar with the UCLA Center for the Study of Women, Price conducted dozens of tours as a longtime member of the Los Angeles Urban Rangers. “Project 51 grew out of my own frustration,” Price recalls. “It seemed like every time I did a tour, I’d ask, ‘Who’s been to the L.A. River?’ Almost no one. ‘Who knows about what’s going on at the L.A. River?’ No one. Even though the river is a huge policy priority, public awareness still lags way behind. I could take out only 40 or 50 people at a time on my tours, so I wanted to do something that potentially reached thousands. That’s when I became interested in forming a collective that dealt just with the L.A. River.”

Yet she had no details in mind when she started contacting likeminded activists. “The idea was to convene this group and start brainstorming. The nice thing about a collaborative group, as opposed to doing it by yourself, is that you can pool your skill sets and ideally come up with something that’s more than the sum of its parts.”

When Price reached out to Carruth and Carruth’s husband, documentary photographer and designer Barron Bixler, the couple responded with ideas, writing skills and design concepts. Freewheeling meetings with Project 51 co-founders — including urban planner John Arroyo, UC Riverside History Associate Professor Catherine Gudis and socially engaged artist Amanda Evans of Portland State University — eventually yielded the group’s core concept: a deck of 5-1/2” by 8-1/2” cards that display a map, activity “prompts” and historical tidbits for 52 on-river and four off-river locations, all packaged as a colorful infographic. The group was joined in these efforts by Erika Barbosa, Lila Higgins, Kat Superfisky, Allison Wyper M.F.A. ’11 and Natale Zappia.

“Because of the uneven way revitalization of the river has proceeded over the last couple of decades, it’s this patchwork of pockets or nodes,” Carruth says. “There have been efforts to create continuous bike paths, but the river is not yet a united conduit of green space that connects communities. The card deck embodies the idea that the river remains fragmented.”

Like all Project 51 members, Carruth and Bixler researched the locations included in the card deck. They embarked on scouting missions to parts of Los Angeles Carruth had never paid much attention to. “We focused on downtown and came across all these unexpected surprises,” Carruth recalls. “Underneath the First Street Bridge on the west side of the river, there’s this shaded breezeway planted with lovely trees where you can take respite from the industrial nature of downtown. When you look up, there’s this portico that Barron and I envisioned as the perfect place for friends and couples visiting the river to reenact the Romeo and Juliet balcony scene.”

Poking around the riverfront’s nooks and crannies offers a visceral perspective that only comes from getting out of the car and into the great outdoors, Carruth says. “Connecting to the river and exploring it — on foot, by bike, by pogo stick — really transforms your relationship with it, because your experience then becomes very tactile and kinetic,” she says. “Most people have probably driven over the river once, or many times, but you get a very different impression when you get up close.”

The challenge of engaging Los Angeles’ car-centric culture inspires modestly scaled optimism in Project 51 co-founder Arroyo, currently a doctoral candidate in MIT’s Department of Urban Studies and Planning. “L.A. is an ‘I’ll believe it when I see it’ kind of a place, and rightfully so,” he says. “Time and time again, many of its traditionally underserved neighborhoods were promised physical community improvement projects that were never realized. When it comes to the L.A. River, people say, ‘Tell me when you get the concrete out of the river.’ But the main goal of Play the LA River is to encourage Angelenos to celebrate the river as a vital civic space now, as opposed to 25 years from now, regardless of whether or not the concrete remains.”

If the U.S. Army Corps of Engineers has its way, at least one segment of the river may soon benefit from a substantial eco-makeover. In May 2014, the Corps proposed a $1-billion plan to restore habitat, widen the river, create wetlands and provide access points and bike trails along an 11-mile stretch north of downtown through Elysian Park.

Price hopes Project 51’s card deck guide triggers interest in every mile of the Los Angeles River, from its origins in Canoga Park to the Long Beach estuary where it flows into the Pacific Ocean. For Carruth, Play the LA River’s brand of infographic activism aims to provoke new relationships between Angelenos and their long-neglected waterway.

“If this takes off,” Carruth says, “what will be most successful about Play the LA River is not the ideas we come up with for the ‘prompts’ for the cards, but what others come up with. We’re trying to create a platform for getting folks to the river, as individuals or as groups. We’re providing a framework for people to organize their own events.”

After suffering decades of neglect, Price notes, the river’s comeback would mirror worldwide efforts to undo years of industrialized overkill. “Many cities destroyed their rivers during the industrial era at the same time that they destroyed their industrial cores,” Price says. “What you saw gaining steam in the 1970s and what you continue to see now is that cities around the world are revitalizing their rivers as a strategy to revitalize their cities.

“The cool thing about the L.A. River is, if you can do it in L.A., you can do it anywhere. We’ve got 51 miles of the most degraded river in the country. It’s very daunting, but also very exciting.”

Visit every location in this photo essay at playthelariver.com and access the interactive Play the LA River card deck.