How a Southeast Side dumping ground became one of the country’s most ambitious urban bike parks, and why the final piece just dropped into place
On Saturday morning, riders will roll their bikes up a 30-foot mound of packed earth on the far southeast edge of Chicago and look down at something the city didn’t have a year ago: a jump line advertised as the longest paved run of its kind in the nation. Below it, on the same five acres, sits an XL line built for people who already know what a berm is and a beginner line built for people who don’t. Tours run from 11 a.m. to 4 p.m. Workshops on the pump track and singletrack run until 2. Bring a bike or rent one on site.
It is, on its face, a straightforward ribbon-cutting. It is also the last page of a story that started with slag.
From Dumping Ground to Design Document
Big Marsh Park sits on the eastern shore of Lake Calumet in South Deering, a neighborhood most Chicagoans could not locate on a map and even fewer had reason to visit before 2016. For more than a century, steel mills used the land as a receptacle for slag, the hardened, reddish, metal-laced byproduct of steelmaking that renders soil more or less permanently hostile to anything green. The last mill on the site closed in 2002. What it left behind was roughly 300 acres of industrial scar tissue.
Cleaning slag out of the ground properly, removing it entirely, was priced at somewhere north of $200 million, a number that ends most park proposals before they start. The Chicago Park District, which took control of the land from the city in 2011, chose a different math. Rather than dig the slag out, they buried it, capping the site with more than 2,500 truckloads of clean fill hauled in, largely in-kind, from construction sites around Chicago. On top of that cap, they decided to build something people who love dirt tend to appreciate: a bike park.
That decision was formalized in a 2014 framework plan, a document that laid out two jump lines, a dirt pump track, and a beginner-friendly singletrack for the park’s southwest corner. It also set the long arc that Saturday’s opening finally closes. The bike park and the park’s northern trails opened to the public in 2016, following extensive environmental remediation. The place did not officially carry the name Big Marsh until 2018.
The Money Behind the Marsh
None of this happened because a government line item decided a slag dump deserved a bike park. It happened because a nonprofit called Friends of Big Marsh spent a decade convincing companies, foundations, and individual riders that it did.
The organization’s fundraising has followed a familiar nonprofit choreography: seed money from grassroots donors, a matching challenge from a bigger funder, then a headline gift that makes the math work. For the Big Hill project specifically, that meant $35,000 from neighbors and small donors, a $100,000 gift from a major individual donor, and a $250,000 matching pledge from the Builder’s Initiative, the Chicago-based philanthropic arm connected to the S. Bass Pritzker family, that was designed to pull in exactly the kind of grassroots giving it matched. SRAM, the bike component manufacturer headquartered a few miles away in Chicago, added $200,000, a meaningful gesture from a company whose products are, quite literally, what riders will be testing on the new hill.
The campaign carried the name “Big Hill, Big Future,” and by the time Friends of Big Marsh and the Park District broke ground in a ceremony last October, it had pulled in the full $1.1 million needed to finish construction. That figure sits comfortably inside a longer pattern of support for the park: an REI Cooperative Action Fund grant to Friends of Big Marsh for general operations, a $900,000 state grant in 2020 that helped fund the park’s first campground plans, and the $7.8 million Ford Calumet Environmental Center, designed by the Chicago firm Valerio Dewalt Train and opened in 2021, which gave the park a permanent building instead of a folding table under a tent.
Executive director Paul Fitzgerald has been the connective tissue through most of it, courting donors while also, by his own account, still figuring out how to reach the birders who wander the park’s northern half looking for least bitterns rather than berms. Big Marsh, in other words, is trying to be two parks stitched into one, and the fundraising has had to serve both audiences at once.
The investment shows up in the attendance numbers. Friends of Big Marsh counted more than 13,000 participants across some 300 organized events at the park last year, on top of the tens of thousands of people who simply showed up on their own to ride, walk, or bird-watch. The organization also runs adaptive cycling programs with partners including Envision Unlimited and Shirley Ryan AbilityLab, a detail easy to lose in a story about jump lines but central to what Friends of Big Marsh says it is actually building: not just a bike park, but eco-recreation open to people who would otherwise never get near a mountain bike trail. There is a Roman Villarreal sculpture near the pump track, its surface dotted with small metal butterflies by Pilsen artist Frank Diaz, a reminder that Big Marsh has never been only about speed and dirt. It is also, deliberately, a place to slow down.
What Actually Opens This Weekend
The Big Hill itself is not subtle. It rises 30 feet over five acres of the park’s core bike area, built around eight gravity-fed trails that progress from beginner-friendly to genuinely intimidating, plus pedestrian access for anyone who wants to walk up and simply watch. The asphalt jump line, paved rather than dirt, is the piece the Park District is billing as the longest of its kind in the country, a claim that will likely draw out-of-state riders the way a good skatepark draws skateboarders: word of mouth, then Instagram, then a road trip.
The XL line is built for riders who have already outgrown the park’s existing intermediate terrain. The beginner and intermediate features on the same hill exist so that a parent and a kid, or a nervous first-timer and a friend who has been riding since middle school, can occupy the same five acres without one of them being miserable. That layering, small next to XL, beginner next to expert, is the same design logic that has defined Big Marsh’s bike terrain since the 2014 plan, and it is arguably the reason the park has become a genuine destination rather than a local curiosity.
Chicago Park District General Superintendent and CEO Carlos Ramirez-Rosa framed the opening as more than a ribbon-cutting, calling it confirmation that the Southeast Side has become a real hub for cycling culture, and it is hard to argue the geography does not back him up. Fitzgerald, for his part, has said the goal now is drawing more experienced riders to a part of the city that spent decades being defined by what left it, the mills, the jobs, the population, rather than what might come to it.
The Longer Ride
There is a version of this story that ends with the ribbon cutting, the tour groups, the kids on rental bikes wobbling down the beginner line while their parents hover nearby. That version is true, and worth showing up for.
South Deering’s population has never really recovered from the mills closing, and the neighborhood has the lowest population density in the city to show for it. That is the unglamorous backdrop against which “regional bike destination” gets pitched as an economic development strategy, not just a recreation upgrade. It is a bet that people who would never otherwise drive to 116th and Stony Island will do it for a jump line, and that some of them will notice the rest of the Southeast Side while they are down there. It is the same bet the Park District has made a few miles north at Steelworkers Park, where a former ore wall now hosts a climbing gym instead of raw material. Reclaimed industrial land, it turns out, is Chicago’s newest renewable resource.
But the more interesting version is the one underneath it: a park built on the theory that you do not always have to remove poison from the ground to make the ground useful again. You can cap it, invest in it, and let a different kind of value grow on top. Big Marsh’s birders, who have documented the site’s slow return of least bitterns and black-crowned night herons, are living proof that the marsh itself is healing on its own schedule. The bike park, meanwhile, has healed something else, a Southeast Side reputation that had calcified almost as hard as the slag underneath it.
Whether the Big Hill becomes the regional draw Friends of Big Marsh is hoping for, pulling advanced riders away from established dirt destinations elsewhere in the Midwest, will take a few seasons to know. What is already true is that the last blank space on a decade-old framework plan just got filled in, on a hill made of borrowed dirt, over ground that steel mills spent a century trying to ruin.
The mound will not care about any of that on Saturday. It will just be there, 30 feet of it, waiting for someone to drop in.
