The report gives results of a study to locate candidate houses for a proposed radon mitigation research and demonstration project in North Florida. The effort involved: identification of target geographical areas, radon monitoring in identified clusters, and house characterization. Selection of target areas with a potential for elevated indoor radon started with a review of a statewide radiation study completed in 1987 and examination of the local geographic pattern observed in a 1986-87 pilot study of the Gainesville area. This effort indicated that North Florida target areas could be selected on the basis of the near-surface occurrence of the Hawthorn geological formation. Volunteer houses for radon monitoring in Alachua and Marion counties were obtained by announcing the study in newspaper articles. Screening measurements were made in about 400 target area houses according to EPA protocols using a vendor-supplied charcoal collector method. Results were similar in the two counties, and distributions were similar in both slab and crawl-space houses.