Aspen-Pitkin County
7,820' MSL
There’s no low way in from the Front Range: both routes cross above 12,500'. Well-covered by cameras and AWOS either way.
Two ways in. Pick one before you leave the ground: both routes cross above 12,500' MSL, so plan your oxygen accordingly. Both finish by turning north up the Roaring Fork Valley, over Carbondale, to Aspen.
North up · Front Range (east) on the right, Aspen (west) on the left
Showing the North · Primary route.
Rollins Pass (Corona Pass)
11,676' MSLOn the Continental Divide in the Front Range, southwest of Boulder. Expect strong downdrafts whenever winds aloft exceed 30 knots.
Weather source: Dakota Hill cam and AWOS.
Berthoud Pass
11,315' MSLUS-40On the Continental Divide between Empire and Winter Park. Same downdraft caution as the other high crossings in moderate to strong wind.
Weather source: Empire AWOS, the Berthoud backup.
Cottonwood Pass (Gypsum)
8,280' MSLEagle County Road 10ASouthwest of Gypsum. By far the lowest pass on either route, and the easy stretch before turning north to Carbondale and up the Roaring Fork Valley to Aspen. Not to be confused with the higher Cottonwood Pass near Buena Vista, a different crossing entirely.
Weather source: Sunlight Mountain AWOS.
This guide gives you the real-time sources: the cameras, the AWOS, and what each pass tends to do in certain wind directions. The Return Rule tells you what to do once you don’t like what you see. What it deliberately doesn’t do is hand you a wind limit, a ceiling minimum, or a turbulence threshold to fly by.
That’s not an oversight. Two pilots crossing the same pass in the same conditions are flying genuinely different flights: different aircraft performance, different currency, different comfort with terrain. A number that’s conservative for one pilot in one airplane can be reckless for another. Setting a universal limit here would mean substituting my judgment about your risk tolerance for your own, and that’s not a substitution either of us should want.
You are the pilot in command. Under 14 CFR 91.3, the decision to go, and the decision to turn around, is yours alone: built from your own experience, your airplane’s actual performance rather than book numbers on a good day, and an honest read on what you’re willing to fly into. This guide’s job is making sure you have the real picture before you decide. Deciding is still yours.
Showing the North · Primary route. Same pass positions as the map below, so you can line up exactly where each frequency change happens.
Hatched segment: known weak or gap reception below 16,000'.
From departure.
Once past Rollins or Corona Pass. Stay on this through the Eagle County overflight: Denver Center is working Eagle Co arrivals and departures and has the best traffic picture there.
After Cottonwood Pass, on through Carbondale and up the valley. Stay with them until they ask you to switch to tower, no further switch needed.
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