Mahaska County Of--oskaloosa, Treasurer 106 S 1st St Oskaloosa, IA 52577 Phone : (641) 673-5482 Business Category Government Offices-County Public Finance Taxation & Monetary Policy Government Offices & Public Schools Mahaska County Of--oskaloosa, Solid Waste Removal & Recycling Information, Landfill 2979 Highway 63 Oskaloosa, IA 52577 Phone : (641) 673-5482 Business Category Government Offices-County Government Offices & Public Schools Mahaska County Of--treasurer Court House Oskaloosa, IA 52577 Phone : (641) 673-5482 Business Category Government Offices-County Government Offices & Public Schools