LA CROSSE, Wis. -

Admission to this year's Riverfest is a pint of blood. At least, that's what some folks are doing to earn their button.

The BloodCenter of Wisconsin kicked off a three day drive Tuesday at the La Crosse Center.

Anyone who donates is getting a free button into Riverfest.

All blood types are needed, but there is a greater need for type o-negative. "We are really encouraging o-negative donors to come in and donate. Those are very special to us. We give those to preemies in the I.C.U, we give those to trauma patients that come into emergency rooms. So we can really use o-negative donors especially right now," said Shari Vanderbush from the BloodCenter.

The blood drive picks up again Wednesday from Noon until 6:00 p.m. and on Thursday from 7:00 a.m. to 1:00 p.m. in the La Crosse Center South Hall B.