Originally Posted by
beachmouse
If you take the northern route, I'd start by looping through Michigan's UP instead of going toward Chicago- lets you hit Pictured Rocks, which is awesome and underrated, and also anything interesting in Minnesota and the Dakotas fairly easily.
I'd tend to agree with that route, except it's probably not real great for getting to San Diego. I did a western road trip a number of years ago (didn't go all the way to California, since that wasn't really our purpose on that trip). For us, starting in Michigan, we went north to the UP, visited Sault Ste Marie, Tahquemenon (spelled wrong undoubtedly) Falls, then started working our way west. We then worked our way west along a somewhat northern route, visting the Corn palace, Badlands, Mt Rushmore, Crazy Horse, Jewel Cave, Devils Tower, Little Bighorn, Yellowstone, Salt Lake City (where we drove part of the Pony Express trail, and also visited the Bonneville Salt Flats), then headed down to Zion and Bryce Canyon, Capitol Reef National Landgrab, then up to the Moab area for Arches and Canyonlands. Then Natural Bridges, the Mokee Dugway (which was kinda neat and unexpected given the terrain we were driving through), goosenecks of the San Juan, 4 corners, Mesa Verde, Great Sand Dunes, then up and over the 4 wheel drive pass towards Pueblo, up to the Denver area to stay with my Parents. From there, spent some time in Rocky Mountain NP, before finally coming home by I-80 (which is something one could probably use as a torture device). We did the whole loop in about 3 weeks I think, but easily could have taken much longer.
Great trip, but definitely a lot of driving that was involved. For getting to San Diego, if you're willing to take the extra time involved with going North, I'd go through the UP, then go along I-90 and hit some of the things I did along that route, up till about Devil's Tower, then head south to Denver, spend some time in Rocky Mountain NP, head west from there, maybe to the Moab area, then work your way to the western side of Utah, and head down I-15, stopping at Zion and Bryce along the way, then continue roughly along I-15 through Vegas towards San Diego. I think there's a lot you could see along that route without hitting the mind-numbingly boring stretch of I-80 through Nebraska and Iowa (and back when I did that part last, Iowa I think was still stuck at 55 for the speed limit, and it was patrolled pretty signficantly).