This data set is available from the Farm Service Agency. Each slide covers an area of roughly 3 x 2 km, at a scale of 1:100000. The slides are taken in late May or early June usually, for the FSA's crop compliance certification program. We purchased the slide sets from the local county FSA offices. They cost $10 for the first slide and $1 for each additional slide. When projected on a wall with a zoom lens, the slides portray a great deal of spatial land cover information.