Jane,

I LOVE Colorado. Have you been to the Great Sand Dunes (http://www.nps.gov/grsa/index.htm)? If you do the Colorado loop, I would suggest cutting north from Santa Fe and hitting the Sand Dunes on your ways to the Springs. Or, if you've already seen Colorado -- have you done Utah? That's National Park heaven. smile

And to bounce off the Cancun idea -- the Dominican Republic has all-inclusive resorts and may be a little less congested with tourists than Cancun.