This technical memorandum has been prepared to summarize results of drilling, construction, and testing at hydrologic test wells DHRES-12 and DHRES-13. Borehole DHRES-12 was drilled to characterize hydrogeologic conditions in the deep groundwater system in Cross Canyon, west of the Apache Leap escarpment, and to provide a monitoring location for the deep groundwater system during ongoing dewatering operations. DHRES-12 was abandoned prior to completion due to lost circulation and borehole instability. Well DHRES-13 was drilled at the same site to replace abandoned borehole DHRES-12. Monitoring data obtained from DHRES-13 has been incorporated into the RCM hydrologic monitoring program.