On the east side, Loveland area is good, Horsetooth Res, Carter Lake - make a loop of Rist Canyon (steep and car-free!) and Stove Prairie, or loop Stove Prairie over to Cache de la Poudre - which is actually not that awesome of a ride, a little too much traffic. Farther West, though, it's nicer. Off of Big Thompson Cyn, go northwest at Drake on Devils Gulch Road through Glen Haven and into Estes - much nicer than Hwy 34(=Big Thompson), Hwy 36 out of Estes carries too much traffic, but Hwy 7 over to Lyons is excellent. From Estes, you can take Hwy 7 to Hwy 72, the Peak to Peak highway - that's all good (makes a long ride if you do it from Estes.) There is a lot of good riding out of BOulder and Golden too, that incorporate the Peak to Peak. LEfthand Canyon, Golden Gate Canyon, Coal Creek Canyon - can all be strung together for loops of various lengths and lots of climbing.
Look up the "Golden Triangle" (edit It's COPPER triangle)- it's a supported ride, but the loop is very simple to self-support - start at Vail or Copper, go either direction, there are enough stores to get food and water.
Pretty much all the divide passes are good - basing out of Frisco or Dillon, you can ride Loveland Pass, Vail Pass, the Copper Triangle.
Last edited by valygrl; 05-09-09 at 03:50 PM.