Exploration no. 68310 is a Geotechnical (depth 18.5 feet) named: B-4 described in subsurface document no. 13634. The document, a report titled Cedar River Pipelines No. 1, 2, and 3 and Electrical Pipelines was prepared by Hart-Crowser and Associates, Inc. on 01-05-1984 for a Utility project.