The Bureau of Reclamation and the California Department of Water Resources are conducting exploratory work, including clearing, excavation and controlled blasting of rock material in the Basalt Hill area near B.F. Sisk Dam, located between Los Banos and Gilroy, between 6 a.m. to 8 p.m. during April and May. The exploratory findings on Reclamation lands will help identify size and quality of granular material for the planned Safety of Dams Modification project.