Dawson Geophysical is poring over a 100-square-mile section along the Niobrara River in Sioux County.
The work is expected to continue through the end of the year. Once finished, Dawson will forward the data to WhitMar Exploration Co. and Hawkwood Energy to make drilling decisions.
WhitMar says the companies expect to drill a pilot test well in spring 2014.
The newspaper says previous oil projects in Sioux County have met only limited success.