A steamflood recently initiated by Mobil Development and Production U.S. at the Lost Hills #3 oil field in California is notable for its shallow depth and the application of electromagnetic geophysical techniques to monitor the subsurface steam flow. Steam was injected into three stacked eastward-dipping unconsolidated oil sands at depths from 60 to 120 m; the plume is expected to develop as an ellipsoid aligned with the regional northwest-southeast strike. Because of the shallow depth of the sands and the high viscosity of the heavy oil, it is important to track the steam in the unconsolidated sediments for both economic and safety reasons.