Public data is from the Conservation and Survey Department at UNL. A digitized version of the bedrock geology of Nebraska. Primary source is a 1:250,000 series of geologic bedrock maps for eastern and southern Nebraska. Published in the early 1970s, a large portion of the area has been superseded, but not published. The remainder of the state has been published at 1:1,000,000 in 1986, but current mapping is being done on the surface geology, rather than bedrock geology. Updates are planned on a county by county basis.