The 25th anniversary of the American Lung Association of Maine’s annual Trek Across Maine will pedal off from the University of Maine in Farmington on Saturday morning, ending the second 55.8-mile leg of the 180-mile trip at Colby College in Waterville later in the day. The trek will finish Sunday in Belfast.

The three-day trek is expected to raise more than $1.6 million in support of Lung Association research, education and advocacy.

There are 2,500 riders registered to participate, and another 500 volunteers expected to help with traffic control and assist at rest areas.

Motorists are urged to use caution when passing cyclists on the charity ride route.