Almost 3,200 volunteer groups will clean up litter along more than 7,200 miles of Michigan highway as the year's second Adopt-A-Highway pickup gets underway Saturday.

The pickup will run through July 21st, and follows an April cleanup in southern Michigan and early May cleanup in the Upper Peninsula and northern Lower Peninsula for the Michigan Department of Transportation program, which began in 1990.

M-DOT says in 2012, Adopt-A-Highway volunteers collected about 65,000 bags of trash, a cost benefit to the state of $5.6 million.

The volunteers include members of various civic groups, businesses and families. Crew members have to be at least 12 years old, and each group must number at least three people.

Sections of highway are still available for adoption. Adopt-A-Highway signs bearing a group's name are posted along the stretches of adopted highway.

The year's final Adopt-A-Highway pickup will be in the fall, from September 21 to 29.