The objectives of this research were to improve the interpretations of transient electromagnetic (TEM) measurements over two-dimensional subsurface structures. TEM is a surface electromagnetic method employed in fossil energy reservoir exploration and characterization. Electrical measurements find application in (1) assisting in fossil energy exploration mainly in areas where seismic methods yield inadequate data quality, such as volcanic covered terrain, permafrost areas, and the Rocky Mountain Overthrust; (2) mapping contacts between hydrocarbon and brines in shallow producing horizons, and (3) in monitoring enhanced oil recovery processes which cause zones of lower resistivity. The work under this contract consisted of three tasks: (1) Selection of a test site and acquisition of a high density, 3-component data set over the test site; (2) development of finite element modeling algorithms for computing 3-D EM fields over 2-D subsurface structures; and (3) development of TEM 2-D subsurface imaging method. Accomplishments for these three tasks are presented in this report.