Ride Idaho went that direction a few years ago. Great fun. You should be able to visit our site, rideidaho.org, and either find our Eastern Idaho route on file or maybe you can write to the tour director (Julie) and have the maps sent to you.
We climbed up into a wind energy farm on the first day out of Idaho Falls, rode along Pallisades, ended up in Alpine WY for a night, visited a ghost town, dropped by several wildlife reserves, came into the back of Pocatello on a road I didn't know existed, and then took a long flat day to get back to IF.
You really should take advantage of your trip to Idaho to visit the reactor museums at Idaho National Laboratory and the Craters of the Moon National Park (or is it just a National Monument?).
Are you from Idaho? If not, you need to understand that, unlike other NW states like Oregon and Washington, Idaho's smaller towns are linked by a single road. To escape the trucks and car traffic, you must be willing to add significant mileage by taking the section roads that form our rural roadway grids. Wind can be fierce in Idaho. Your route should give you lovely views of the Grand Tetons and you can take a nice side trip to climb up to Grand Targhee out of Victor (I think it was Victor).
An interesting side note: Our long term parking lot was sprinkled every night by really hard well water. All of our cars were covered with scale. The windshields required several careful applications of LimeAway before anyone could drive safely.
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