Having the opportunity to come from Europe and travel the states on two wheels will be a great trip, regardless of where you visit. The time of year being mentioned in the Spring (March 15 – June 15) would be the best time to travel and by trying to make your starting point in say, Southern California would be perfect, because you would be in our hottest areas during the best time and reaching the cooler areas after they have had a chance to warm up a bit.
Your planned route will probably be dictated by what it is you enjoy doing, if you like the hustle of big cities (crowds & traffic), or maybe small towns (generally nicer people, better scenery). Our Mid-West or otherwise known as our Plains States does have a lot of straight roads, lacking mountains and lots of corn & wheat growing, but if you like Western History (cowboys & Indians), you will be required to travel through some of those flat areas to really pick-up on our Western history. I mentioned that because it seems like many visitors I’ve run into from Europe seem to enjoy seeing our Western history (like Wyatt Earp, Doc Holiday, Dodge City, Tombstone, Wild Bill Hickok, Sitting Bull and Geronimo). In order to reach places such as Sturgis South Dakota, the Black Hills, Mount Rushmore or the home of Harley Davidson in Milwaukee Wisconsin you will have to ride through our flat farm country and put up with lots of wheat and corn being grown everywhere the eye can see. But on a good note, if you like the tranquility of wide-open spaces and being alone, you’ll like these areas also.
Realistically, unless you have a couple months, you’ll need to decide what interests you the most. You have plenty of time to decide. I would guess you would want to see places that are different than where you generally ride now. Everyone wants to see California and the Pacific Coast Highway; you’ll like Utah & Arizona because of the Painted Desert, Rock Formations, National Parks and the Grand Canyon. The states of Idaho, Wyoming & Montana offer you Yellowstone, Teton & Glacier National Parks, which will offer you the opportunity to see wild animals (Bear, Elk, Moose to name a few) in their natural environments and absolutely breathtaking rivers, lakes, mountains and 2-lane highways.
The state of Colorado is a bit misleading if you have never been there before. The Eastern 1/3rd of the state will remind you of the moon. Once you reach the cities either Denver or Colorado Springs and everything west of those two cities, Colorado shows you why it is so beautiful and one of my favorite places to own a motorcycle. Because most of Colorado is above 5000 feet in elevation, snow is very likely before May 15th and still possible into our summer months in the higher elevations.
Much of the Mid-Western and Eastern states will have hundreds of small towns, villages and smaller communities in between the large cities. If you avoid the Interstate Highways (highways like I-40 or I-70 or I-75), you will ride mostly on 2-lane or 4-lane roads that should be in good shape for the most part. This area will have a lot of low lying mountains with great sweeping turns, thousands of lakes and rivers, small community atmosphere and little café style restaurants that offer good food. These areas will also offer you the entire history of our Civil War, our Capital and the countless historical areas (too many to mention).
The South Eastern states along the Gulf Coast or the Atlantic Coast will offer you lots of water, beautiful ocean views and many areas where you are allowed to ride your bike on the sand near the ocean. Once inland, other than the types of trees you’ll see growing, the scenery is close to being like the North Eastern part of the country, except the South East will be humid. The humidity can get extremely harsh unless you are used to it. If you enjoy eating the best oranges and peaches, the South Eastern states will provide you with all you can eat. If in Florida, use extreme caution before jumping in that beautiful lake you might find yourself stopping at for a break, because the alligator population in Florida has grown faster than the human population in India and you just might find one sizing you up for lunch.
So like I mentioned earlier, the states will offer you possibly the best riding anywhere in the world and give you the opportunity to see whatever it is that suits your fancy. Time will be your biggest enemy; because once you get here you’ll discover that there just isn’t enough to see all there is to see. So before you and your friends sit down to plot your route, try and decide what it is you want to see and do, and then you choice of routes will be much clearer for you to determine. Either way, have a great time and bring lots of money.
Oh, one more thing. If you prefer to stay in hotels or motels, the cost will usually range from about $100 and up per night with 2 people per room. More in larger cities and places that are “tourist traps” and possibly less in small towns and cities away from the major highways.
If you enjoy camping, there are great campgrounds throughout the entire country. Most of which offer clean showers and bathrooms, cafes, swimming pools and other things you might decide to use. The cost of camping will cost you on average of $8 - $15 dollars per night, more in larger cities or tourist traps. You mentioned your availability of GPS units. If your GPS has the U.S. loaded in them, places to stay (hotel or camp) and places to gas up or eat will be listed. The United States is the “Land of Plenty”, so you should not have any problem finding gas (petrol), food or lodging. Should you decide on Arizona, Utah, Nevada, Wyoming and parts of Texas, if you see a sign that reads “Last Gas for 150 miles”, you best fill your tanks because they mean what they say. The Southwest has areas that are far and few between gas stations.
I hope my two-cents worth helps a little.