Do you want to travel on interstates or on US Highways like
US-20,
US-36 or
US-50? Do you plan on going as far North as the Dakotas? The most direct interstate route from Nashville to Yellowstone is through Missouri, Nebraska and Wyoming. Along these more Southern routes potential stops are towns like Hannibal(Samuel Clement's birth place), Saint Charles (where the Lewis and Clark expedition started), Wintersett(John Wayne's birth place and home of the Bridges of Madison County), the Amana Colonies, Dodge City, Hutchinson (home of a Space Museum and Salt Mine tour), Fort Kearny (on the Oregon Trail), Thermopolis and Cody. If you provide more information about your route and what kind of things you want to see and do along the way folks can likely give you some viable suggestions.
For trip planning I like to use Microsoft Streets and Trips with the add on Point of Interest data from the
Discovery Owners Forum and the
POI Factory. Local Chambers of Commerce and Tourist Information/Welcome Centers are good places to find out about local attractions and activities. The book "A Thousand Places to See Before you Die" is a good source as well. To find things to see and do in any specific location, I also use these websites:
National Parks,
National Wildlife Rufuges,
State Parks,
Scenic Byways,
National Historic Trails,
Legends of America,
Roadside America,
Ghost Towns,
Slot Canyons,
Pow Wows,
Flea Markets,
Rock Art,
Native American Ruins,
Factory Tours,
Waterfalls,
Scenic Railroads,
State Fairs,
Lighthouses,
Breweries in the United StatesWineries in the United States,
Trip AdvisorState Tourism WebsitesFrommers Guide Fairs and Festivals
Safe travels!
Trailertraveler