The Jasper County Genealogical Society is now located in the County Annex Building at 115 N 2nd Ave E in Newton, Iowa. They are open on Thursdays and Fridays 10 AM - 12 PM and they reopen from 1 PM - 3 PM. They are also open on the first and third Saturdays of the month from 9 AM - 12 PM. There is a charge of $12.50 for research that includes the cost of copies and postage. For any other questions please call 641-792-5951.
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