I am planning a climbing trip for this coming Summer. I am leaving from Chicago the last week in May, aiming to hit Washington/BC for most of July, and am planning to be back by the middle of August. I am very interested in hearing personal experiences/tips for a trip like this, as well as suggested areas, and any climbers who are looking for partners along the way.
There are a couple small but cool spots on the way west for you. I'd do something in WI (Devil's Lake, Necedah, Granddad's Bluff) then hit up Palisades State Park (outside Sioux Falls), then you drive for a few hours and magically you are in the WEST! Drive through Badlands Nat'l Park, see the dirt, maybe some bison. Now comes the rock: All the stuff around Mt Rushmore/Needles (trad and sporty sport), head north to Spearfish (sport), continue west to Devil's Tower (where you'll make use of that annual Nat'l Parks pass you bought at Badlands), next stop Ten Sleep Canyon for 5 star sport and beer, west to Teton Nat'l Park (don't get in over your head) and Yellowstone Nat'l Park (you've saved so much money with that annual pass!), roll down to southern Idaho for some time at City of Rocks. After that the highway heads NW through Boise and into OR/WA. Those are my favorite summer stops along your route. There is really good bouldering north of Seattle in Leavenworth, and great(?) single pitch trad at Index on the way up to Vancouver. Squamish and Penticton are the only climbing areas I've been to in BC but there are MANY. Happy travels.