The Mississippi River Trail (abbreviated MRT) is a designated bicycle and pedestrian trail that traverses the shores of the Mississippi River in the United States. The trail extends from the headwaters at Lake Itasca in Minnesota to near the mouth of the river in Venice, Louisiana. Much of the trail’s 3,000 miles (4,800 km) follows roadways used by motor vehicles, although some of the route is on multi-use trails. The segment in Minnesota has been designated as U.S. Bicycle Route 45 (USBR 45), part of the U.S. Bicycle Route System.