The state Department of Natural Resources is now grooming 78 miles of trails for so-called "fat bikes."

Fat bikes have exploded in popularity recently in Minnesota, especially in the winter. The bikes' extra wide tires with very low pressure are designed to float over a couple inches of snow.

But as the number of fat bikers has grown, so has the number of conflicts with other trail users, especially snowmobilers.

• Earlier: As fat bikes gain popularity, trail conflict follows

"There are some safety concerns," said Andrew Korsberg, state trail program coordinator for the DNR. "Snowmobiles go very fast, a lot of the trails are hilly and windy, so we're trying to provide some good places to go fat biking."

The DNR is grooming trails for fat biking at Jay Cooke, Split Rock and Fort Snelling State Parks, as well as the Luce Line State Trail in Wayzata, and the Gateway State Trail in St. Paul.

That's in addition to 20 miles of trails at the Cuyuna Country State Recreation Area near Brainerd. Cycling groups in the Twin Cities and Duluth also groom mountain bike trails for fat bikes.