A lot depends on your subject interest, i.e., wildlife, wildflowers, scenics, etc., not to mention your budget and travel mode… plenty of great suggestions already but you might also consider doing the Colorado/Utah loop, otherwise known as the ‘Great Circle’. You can get everything from wildlife, fall foliage, wild rivers, red rock formations, waterfalls, desert landscapes, etc. For this to work, Fall is your optimal timing simply because the weather is generally very pleasant, the aspens are turning, wildlife is active and most importantly, the crowds have mostly dissipated.
Without belaboring the obvious, here’s a basic itinerary, starting the middle of September in Denver… First, head to Rocky Mountain NP (wildlife and leaves are peaking), then down to Aspen (Maroon Bells, etc.), back over Independence Pass to Crested Butte (Kebler Pass – largest stand of Aspens in the world). From there, head to Montrose (stopping at the Black Canyon of the Gunnison NP) and then down to Ouray, over Red Mountain Pass into Silverton and then Durango – you can also take an alternate route through Telluride and over Lizard Head Pass. Durango is the jumping off place for Mesa Verde NP and then on to the Colorado Plateau area which has an over abundance of world famous ‘red rock formations’, e.g., Monument Valley, Canyon de Chelly, Grand Canyon NP, Zion NP, Bryce Canyon NP, Capitol Reef NP, Canyonlands NP, Arches NP, etc., to name just a few options – lots of travel, lots of photo ops… in truth, you could spend your entire four weeks in just a few of these locations… it should also be noted that these areas are also great for stargazing, astrophotography, etc.
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