Frank and Betty Koller of Manitowish Waters have donated $5 million to the Marshfield Clinic to go toward medical research.

NewsChannel 7 caught up with the couple Friday at the dedication of the Marshfield Clinic’s new Laird Center for Medical Research to see what prompted them to make the generous contribution.

"We just enjoy the Marshfield Clinic,” Betty Koller said. “We've come here for years. In fact, I was about 12-years-old when I first started coming here. I'm a few years older now - about 70 or 80."

The Kollers became successful growing cranberries.

They say they would have given the money to family but don’t have any.

Their donation is the largest single donation ever made to the Marshfield Clinic.

Marshfield Clinic's CEO says the impact of the couple's donation will be felt at the medical facility for years to come.