You'll want to stay one more day!
One full day at Mesa Verde works for many visitors, and many others spend 2 days in the park. But regardless, the next question is "what else?".
The Durango Silverton narrow gauge steam locomotive from the 1800s is the second premier area attraction for the history buffs. Go rent Butch Cassidy and the Sundance Kid to get a glimpse - that's the train! (You’ll need advance reservations in the summer for the train.) There is also a railroad museum where you can climb aboard the engine!
Horseback riding, hiking, biking, river rafting, four wheeling, lots more archaeology round out things to do here. And of course, don't forget SHOPPING!
(PS: I don't know who to credit for the kid on the pony - but it was too cute.)