The results of a survey to determine the top off-road trails in the USA are in, you can find the results for 2015, State by State (if a State is missing it was because there were not enough responses for a result) at http://www.partcatalog.com/blog/2014-top-off-road-trails-in-america/.

Here are the results for 2014:

2014 Top Off-Road Trails in American Infographic via PartCatalog