Mayfield, Ky to Portland Oregon

Do you want to see anything in particular along the way?

Get as far north as possible. Your choices then are MtRushmore and the black hills area. Glacier, Custer Battlefield, and or Yellowstone before heading to PDX.

The freeway through NE and WY is mostly flat and easy driving all four lane using 70 and then up to 80. Climbing really starts west of Cheyenne and cross winds can be a problem. There are a good choice of decent State Parks west of Omaha (arch is worth a visit we have used. There is also a Oregon Trail exhibit that spans the freeway that is very interesting. Would not go north to 90 unless you want to visit the Black Hills, but don't go when the Bike Rally is on in early Aug.

My personal preference would be to take the I-90 route. Mostly because I've found that the road conditions and truck traffic were better on I-90 than I-80. To be fair, it's been a few years since I've been on I-80 west of Lincoln. There's been a lot of road construction on I-80 in Omaha the last few years and it's still going on, but it's not too hard to navigate; get in the middle lane and stay there all the way through Omaha. The previous poster is correct: early to mid August is a bad time to go through South Dakota. Not only will the motorcycle traffic be really heavy throughout the state, but finding a camping spot in the western part of the state will be difficult to find and, if you do find one, it will be a minimum of 2-3 times the normal value; I'd be surprised if you could find a spot for less than $75/night. Once you reach the Missouri River at Chamberlain (the view at the rest area is great)the terrain changes significantly and becomes a lot more interesting. There are also a lot of tourist attractions along the way, some good, some not so much. Hope this helps.