Having lived in Salt Lake City and Denver, I can attest to the weather in March being a crapshoot in Utah, Wyoming and Colorado. I now live in the mountains 85 miles west of Denver where, traditionally, we get the most snow of the season in March and April. When I get cabin fever and leave here every March (Texas Rally this year), I'm fortunate in that I have only two smallish mountain passes and about 3 hours towing to get into New Mexico. It's another 3 1/2 hours on south to Albuquerque where I traditionally stop and de-winterize, so I only need a one day window. I'd stay south as much as possible. I've been in snow (not towing) on 40 at Flagstaff in early March, so......If you do take 10 and have the time, stop in Tucson at Catalina State Park. The flowers should be coming into bloom and it's a great location. Stopped in last spring (2nd year) intending to stay a week and ended up staying three. Happy trails