I'm from Buffalo, Wyoming and have some strip maps I made a few years ago crossing northern Wyoming. The Bighorn Mountains are nothing to laugh at - big climbs - esp. from the West, 2000m.
I also have route guides for crossing Idaho through the Sawtooth Mountains. As for the Great Plains - if you ride through the Black Hills of South Dakota you will be surprised how lovely they are - plus by late July they are MUCH cooler. You may want to do a sunrise ride thru Badlands N.P. - but remember as you get out on the Great Plains it will be HOT!! 40C or more. Best to ride super early - from sunrise to 11am - then quit. There is a fabulous route - Nebraska Hwy 12 - that runs right on the NE/SD border and has very little traffic.
I've been searching old posts for route information. I'm heading West from Virginia to Madison, WI, and then more or less due west from there (home) to Yankton SD. I think this is where you might be able to help me.
I'm thinking about taking 12 or the Cowboy Trail across northern Nebraska, and then cutting north at Valentaine to the Badlands, and then west to Rapid City/the Black Hills.
From the Rapid City I'd like to head South on the trail with a detour for Mt. Rushmore, and from there I would like to make my way to Yellowstone/Grand Teton. I was thinking about skipping the Big Horns and making for Douglas, Casper and Jeffrey City, there joining up with the TransAmerica Trail to Yellowstone/Grand Teton. My concern is that there appear to be few towns or services between the Black Hills and Jeffrey City, with a huge stretch after Casper with much of nothing. Am I picturing this correctly? Is there a better route from the Black Hills to Yellowstone?
I'll likely be solo after the Badlands, if that makes any difference. I'll probably arrive in the Badlands around the third week of June, 2015. I'll most likely be on a recumbent. I tend to tour loaded, but I don't tend to carry my own cooking gear, preferring to stop at cafes etc., especially where I'm solo.
Thanks for any advice.