Authorities say that 47-year-old Gary Rolls had an imappropriate relationship with a neighborhood girl starting two decades ago when she was 9 years old.
Kent County Circuit Judge Judge Dennis Leiber also gave Rolls five years' probation at Thursday's sentencing in Grand Rapids.
Rolls pleaded guilty May 13 to illegal use of a computer, tampering with evidence and fourth-degree criminal sexual conduct. He had been scheduled to stand trial in June on four counts of first-degree criminal sexual conduct.
The victim told the judge she now has "a very hard time trusting people."
Rolls resigned his county commission seat in December 2013.