I have completed making Lake Oahe in North and South Dakota all one chip. I have the latest survey down to 32 feet and contours above normal pool.I used the old topos before the lake was flooded. You can see also the aerial imagery when the lake was 32 feet low in 2007. The old topo show roads trees,foundations and a lot more. I have also completed Devils lake with the latest survey of one foot contours and aerial imagery when the lake was at it lowest approx. 50 foot low. I will have Lake McConaughy in Nebraska done about a week and I have the original survey sheets that shows all the roads trees foundations etc. I also have the aerial imagery when the lake was50 feet low. You can see all this on your Lowrance GPS. Late models only. You can see screen shots of most of my Lakes on my website
Jack Baker 913 441 4241.
Greatplainsmapping.com