Texas is where I was. I can't verify anything in Utah or Oklahoma. There are some wide open spaces in Oklahoma, so I wouldn't be surprised to find 85 there. IIRC there is a toll road through an empty stretch of land, so might be there. I-10 over in West Texas is a good road for high speeds. There is nothing between San Antonio and El Paso, so at 85, you'd barely keep up with traffic. Surprisingly, the Florida Turnpike is pretty good for high speeds as well. It's a 70 mph speed limit, but 70 was dangerously slow last time I was there. I was 80ish and people were flying past me. I-90 up in South Dakota is also good for high speeds. Just be sure to slow down around Rapid City. It's a 65 through the city (maybe 60, I'm not sure) and I frequently see cops. Rarely see someone pulled over so I don't think they are too strict about the posted limits.
My Experience here in the Pacific Northwest, and the West Coast:
Washington:
*Western Washington speed limit is 60mph. People don't know how to drive here! I-5 From Centralia to Everett 75-80mph on a motorcycle in HOV the cops don't usually mess with you too much.
*Rest of the freeways.. I-90 the speed limit is 70, you can do as much as 80-85mph on a bike fine.
Oregon:
*The most you can "get away with" is ~75mph without problems!
California:
70mph on most major Freeways...
~90mph in reality. My kinda state!
Idaho:
75mph on most major Freeways...
~90mph in reality.
Montana:
75mph on most major Freeways...
~90mph in reality.
Utah:
75mph on most major Freeways...
~85-90mph in reality.
Colorado:
75mph on most major Freeways...
~85-90mph in reality.
Nevada:
70-75mph on most major Freeways...
~80-85mph in reality.
Arizona:
75mph on most major Freeways...
~85-90mph in reality.
I don't know much about the east coast, but I love the golf coast and Florida. You gotta watch those Florida downpours though! Suddenly dropping from ~85mph all the way down to 35mph with hazard lights is a bit scary for the uninitiated. I did it once in a convertible 6 years ago. I'm not sure I'm up for it yet on the Goldwing. I would say the two worse states to drive in are North Carolina & Western Washington state. That is of course aside from any major city like new york city for example.
I bet Oregon is probably the toughest state to do a BBG in. I would like to see the map used for that state. Washington state and Idaho would be easy.