The Jasper County Genealogical Society is open on Thursdays and Fridays 10 AM - 12 PM and they reopen from 1 PM - 3 PM. There is a charge of $12.50 for research, that includes the cost of copies and postage. For any other questions please call 641-792-1522.
Some other resources to try:
Des Moines Genealogical Society (515)-276-0287
State Historical Society of Iowa (515)-281-6200
Iowa Department of Cultural Affairs, Library Archives Bureau & State Historical Museum