If you’ve been in the Arb recently, you may have noticed construction underway near the intersection of Highway 19 and Spring Creek Road. A tunnel is being created underneath Highway 19, which will be a crucial piece of a new segment of the Mill Town State Trail between the south end of Northfield and the historic Waterford Bridge!
The project has been in the works for thirty years. Soon into the start of planning in 1994, the City of Northfield and Minnesota Department of Natural Resources realized they would like to have the trail pass through the Carleton Arboretum, and began discussions with the college to see if that would be possible. Arb Director Nancy Braker took up that discussion in 2007, and has worked to make a trail plan that primarily follows the edge of the Arb. When the new bridge over the Cannon River was built in 2009, space was left for the trail to pass underneath to access the historic Waterford bridge. The project will be completed by the end of 2026.
This route was chosen to minimize disruption to the Arboretum, while allowing the trail to pass through a convenient and beautiful path. Because it follows pre-existing trails and parallels the road, there will not be much increase in human impact to the Arb; larger wildlife like deer are already impacted by the road crossing. Trail users may need to watch out for smaller creatures like salamanders, frogs, toads, and snakes, though, which could be out sunning themselves on the asphalt on cold days! Runoff will be managed by a system of culverts and vegetated ditches where water can infiltrate.
Arb staff are excited that the trail will provide a safe way for visitors to cross Highway 19, and a good place to walk when the other trails are muddy. It will also make access to the far side of the Arb easier for those on bikes—just remember to continue deeper into the Arb only on foot to help us minimize the trail’s impact!
While the trail is still being completed, try taking a long walk in the Arb to visit the Waterford bridge, or check out the section of the Mill Town Trail that is already completed between Northfield and Dundas!
- Klara Kjome Fischer ‘26 for the Cole Student Naturalists
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