We have discovered a 1:250,000 toposheet for Columbus, Ohio, published 1972, that is listed as "experimental printing" and shows 4 classes of slope zones (<5%, 5-10%, 15-30%, >30%) in yellow and brown shades.

Can anyone tell me if this was a one-off or are there other 1:250,000 topo sheets of the coterminous US that also show slope rather than topography?

We're not sure whether to catalogue this map as a single, a series, or just include a note about it in our US 250k topo series record. 

Thanks

Brendan Whyte

National Library of Australia