Safe passage for turtles near Big Marine Lake

A snapping turtle crosses the road in Washington County.

The year after my husband and I bought our first home, the city built a new road between our neighborhood and a small lake just north of us. Within a couple of weeks, the road had become a popular short-cut for drivers looking to avoid busy Hwy 42. One day, early in the summer, I spotted an enormous snapping turtle slowly making her way across the new road toward a scrubby grass area opposite the lake. She was so big that I couldn’t pick her up even after I went home to grab thick gloves; it eventually took three of us, heaving and hauling to get her out of the road and up over the curb so that cars could pass. I think about that turtle often, when I see other turtles crossing roads, and how bewildering it must be for them to head off to lay their eggs in the spring in the same place where they have always laid them, only to find a giant swath of asphalt suddenly in their paths, or a house and lawn, where a gravelly field once stood.        

Scientists estimate that painted turtles can live as long as 40 years in the wild, while Blanding’s and snapping turtles can live more than 70. Female turtles often travel relatively far distances to find suitable habitat to lay their eggs (up to half a mile for snapping turtles and as far as one mile for Blanding’s) and after the young hatch out of their eggs, they complete the reverse journey from upland nesting sites back to the water. Most turtles will return to the same nesting locations year after year, but as the metro area continues to grow, there are more and more obstacles in their paths. Many are hit and killed by cars along the way and species numbers are declining as a result.

A newly installed turtle crossing south of Big Marine Park will help to protect threatened Blanding’s turtles.

This year, Washington Conservation District (WCD) and Washington County are working together on a project to improve habitat for turtles, as well as other reptiles and amphibians, in Big Marine Park Reserve. The part of the project getting the most attention is a special tunnel, just installed under Hwy 4, to provide turtles with a safe passage in the spring when they move from their wintering homes beneath the ice near Big Marine Lake to their nesting areas in the wetlands south of the highway. The tunnel is part of a $50,000 research project funded by the Minnesota Department of Natural Resources, the University of Minnesota, the Herpetological Society and Carnelian-Marine-St. Croix Watershed District. 

County Parks and WCD staff expect many kinds of turtles to use the new road crossing at Hwy 4, but local biologists are especially interested in protecting Blanding’s turtles because of their threatened species status.  Blanding’s turtles rely on a mixture of intact wetlands, lakes, grasslands and sandy, rocky open areas for breeding and nesting.  Northern Washington County, including Big Marine Park Reserve, contains this special mix of habitat types and, therefore, is one of the few places in the state where Blanding’s turtles still roam. Other reptiles of conservation concern in the park include snapping turtles and the eastern fox snake.

If you are interested in helping to protect turtles, here are some suggestions:

  • If you live in a rural area, minimize road ditch mowing until late summer as turtle species often nest on roadsides and may be traveling through the road ditch.
  • If you live on a water body, leave fallen logs in place to create basking locations for turtles. Also, consider completing a shoreline restoration project to improve habitat. Visit for more info.
  • If you see a turtle crossing the road, carefully help it across in the same direction it is traveling, but only if it is safe to do so. You can also download an app to your phone to help track locations where turtles are frequently crossing roads in the metro area. Data collected will be used to generate maps that can be used by conservation agencies and highway departments in the Twin Cities area to prioritize and develop safer crossing areas. Go to for more info.