T-minus one day until the trip commences. This time tomorrow (as I type) I will be on the way to Lexington for a doctor's appointment, after which I head to my brother's to start the journey.
At least it looks like I-70 in Glenwood Canyon will be back open, although I'm sure the scenic nature of the area will be affected by the slide and the ongoing construction work. This probably means no new counties in Colorado (or New Mexico, Oklahoma, Texas, or any of the other states that would have been impacted by an alternate route) unless we hit something in the northwestern part of the state if we go to Dinosaur.
North Dakota and Montana will be new states for me. That will put me up to 46 total (lacking only Washington and Oregon in the lower 48, and obviously Alaska and Hawaii to round out the 50). I'll get new counties in Michigan, Wisconsin, Minnesota, Idaho and Utah, and possibly Colorado. The only non-state route clinch I foresee is US 2 in North Dakota (owing to the route's second foray into Wisconsin, which we'll miss, and the closure mentioned upthread in Minnesota). Possibly US 163, depending on how much of it we end up driving.