From abandoned railway to wildlife corridor: How Wisconsin's old tracks became a green lifeline

A railway line in southwestern Wisconsin that hasn't carried a train since 1964 is now one of the busiest routes in the region, but today the traffic moves on hooves, wings, and two feet instead of steel wheels. The Elroy-Sparta Trail, the first rail-to-trail conversion in the United States, has quietly transformed from an abandoned industrial corridor into a vital green passage for wildlife, connecting forests, wetlands, and prairies across the driftless hills.

The 32.5-mile corridor, originally part of the Chicago and North Western Railway's main route linking Chicago with the Twin Cities, was built in the 1870s. It cut through three hand-dug tunnels and passed small farming towns before a more efficient bypass rendered it obsolete. After decades of declining traffic, the railway abandoned the line in 1964. Rather than let it sit idle, the state of Wisconsin purchased the corridor and opened it as a public trail in 1967.

The trail earned a National Recreation Trail designation in 1971 and has since inspired a national movement that has converted over 25,000 miles of former railroad corridors into recreational trails across the country. But its ecological value has quietly outlasted its recreational role.

How an old rail line became a wildlife corridor

Once rail traffic stopped, the cleared gravel surface gradually gave way to surrounding ecology. Grasses and wildflowers spread across the old rail bed, while wooded slopes crept closer, filling in what had been kept clear for passing trains. The corridor now winds through a mix of prairie, wetland, and farmland, creating a patchwork of habitats that would otherwise sit disconnected across the agricultural landscape.

That kind of uninterrupted strip of vegetation is exactly what makes an old rail line valuable to wildlife. Many animals rely on continuous cover to move safely between feeding grounds, nesting sites, and water sources without crossing open, exposed farmland.

A peer-reviewed study titled From Right-of-Way to Greenway: Parameters for the Ecological Function of Midwestern Rail-Trail Corridors, published in the journal Fábos Conference on Landscape and Greenway Planning, examined former rail corridors across Iowa's Corn Belt region. The researchers noted that large tracts of public conservation land are scarce across the intensively farmed Midwest, making long, connected strips of vegetation like former rail corridors unusually valuable for helping species move through an otherwise fragmented landscape.

Using GIS mapping and drone photography, the study's authors assessed how effectively these corridors could be managed not just as recreational paths but as genuine green infrastructure supporting wildlife movement and habitat.

What this means for Iowa's landscape

For Iowa, the lesson is clear. The state's Corn Belt region shares the same fragmented agricultural landscape that makes connected habitat corridors so valuable. While Iowa has its own network of rail trails, the ecological potential of these corridors remains largely untapped.

The United States Fish and Wildlife Service notes that wild animals need functioning routes to complete their life cycles, whether that means a narrow strip of vegetation connecting two patches of forest or a much larger corridor spanning hundreds of miles for migrating elk, deer, and pronghorn. Old rail corridors offer a smaller but no less useful version of that same principle, threading continuous cover through farmland that would otherwise leave little room for animals to move between habitats.

More than a recreational trail

More than half a century after the last train passed through, the Elroy-Sparta corridor now sees close to 60,000 visitors a year, drawn by its crushed limestone surface, quiet river crossings, and three cool, dark tunnels that once guided locomotives through the hills. Yet its role as a functioning ecological corridor has quietly outlasted its role as a recreational trail, offering continuous cover for birds, deer, and smaller mammals that move along its length largely unnoticed by cyclists and hikers.

What began as a stretch of abandoned industrial infrastructure has become something closer to a long, narrow nature reserve. It is proof that a landscape given enough time and room can find its own way back to something resembling wilderness, even along a route humans built for an entirely different purpose.

Frequently asked questions

How long is the Elroy-Sparta Trail?

The trail is 32.5 miles long, connecting the towns of Elroy and Sparta in southwestern Wisconsin.

When did the railway stop running on this line?

The last train ran on the line in 1964, after decades of declining traffic following the construction of a more efficient bypass.

What makes old rail corridors valuable for wildlife?

They provide continuous, uninterrupted strips of vegetation that allow animals to move safely between habitats without crossing open, exposed farmland or roads.