This document summarizes the challenges of mapping crash data from Riverside County onto a roadway map. Only 23% of crashes could be automatically geocoded due to incomplete address information. A customized application helped map an additional 44% by accounting for distance and direction from intersections. Manual review mapped another 12%. Multiple candidate matches, differences between state and local road names, and human errors in the crash data contributed to the remaining unmapped crashes. Better data quality procedures and custom mapping software can help reduce errors and improve crash location mapping.