In October and November 2016-2017, transient electromagnetic (TEM) data, also called time domain electromagnetic (TDEM) surveys, were acquired at 120 locations in the Genesee Valley, Livingston County, New York, in order to characterize the subsurface resistivity structure in support of a U.S. Geological Survey groundwater investigation. The TEM data were collected as part of a project to evaluate geophysical methods to characterize the valley-fill sediments, underlying bedrock, and salinity of the subsurface. TEM data were collected using an ABEM WalkTEM unit (acquisition software V 1.1.0 and newer) using two transmitter loop (Tx) sizes, 100 by 100 meter square and 40 by 40 meters square, a center-loop receiver (Rx) that is 0.5 by 0.5 square meters in size (with an effective area of 35 m^2), and dual currents of about 2 and 11 amperes (A). In addition, a second center-loop receiver, 10 by 10 meter square in size (with an effective area of 1400 m^2) was used. Both receivers were centered and concentrically nested inside the Tx loop. The Tx measurement cycles were stacked 10 times, and 1-5 measurements were taken at each site. Multiple surveys collected at the same location were stacked, filtered, and averaged for each Tx current and set of Rx measurements. This data release includes the raw and processed TEM data and inverted soundings showing resistivity (in ohm-m) with depth.