Corona (aka Rollins) pass is a high-mountain pass that crosses the continental divide between Boulder and Winter Park, Colorado. it was the the only way the trains went over the mountains until the Moffat Tunnel was built in the late 1920s.
Today, you can drive up the pass in the summer-time in a high-clearance vehicle, mountain bike it, and in the winter it becomes a high-volume snowmobile route. I'm also one of the crazy people that ride the snow bike up it.
For the most part, it is a relatively easy ride. It's 2-3% grade most of the way, and well packed and groomed for the snowmobilers. Depending upon where you start though, the early part of the ride is much harder. The easiest access point for me is a trail called Buck Creek, which is more of a 6-10% grade, and on snow, that is brutal.
On the route I took yesterday, it was about 8 miles up and 2,000 ft of climbing. The challenging thing about this ride is that you will sweat hard on the way up, even if it is cold out, but coming down you've got to deal with having cold, wet skin, the wind, and lack of a high heart-rate on the way down. Try as I might, I am not a skilled enough rider to go real fast downhill on the snow without wiping out. Luckily, since we're in spring conditions, yesterday was perfect. It was actually hot on the way up (temperature in the 28-30º range), but on the way down it had crossed the freeze line and there was enough snow I wasn't cooling off too much. It made for a really pleasant ride. When I last did this in January, I had some mild frost-nip during the long trip down.
The Strava ride is here:
https://app.strava.com/activities/268203071
A couple of panoramas of at the top near the ridge of the divide. You can see the snowmobiles still head up to the top of the ridge and over, but at this point I was too wore out to climb that grade. If you zoom in closely, you can actually see three crazy para-skiers doing their thing right along the ridge. Fun! The other panorama that looks down-valley is looking at Winter Park Resort and the town, to the right, and Fraser, to the left.
Since this route follows the old rail line, there is a lot of old railroad history there. Right before tree-line is the famous R-i-flesight Notch railroad trestle (dashes to avoid the dumb censor). You can see it in this picture, but enough snow has fallen to completely obscure the fence that keeps people off of it.
Now, compare to that to the same point in January, where a good 2-3' less snow had fallen.
There are a ton of amazing snow-bike and summer mountain-bike rides to do in this valley. You should come visit
