Begin at Kenosha Pass trailhead. Best to get an early start if possible, as this trail took us much longer than we thought it would. The trail out of Kenosha is fairly easy and definitely scenic. It has a balance of uphill and downhill, although it does climb more as you get closer to the Georgia Pass area. This section is very lush and can be pretty treacherous when wet as there are many roots on parts of the trail that made for some slow going. Weather is unpredictable here too, so plan for bad weather!
The ascent up to Georgia Pass is more or less an easy climb, although the altitude (you are just above treeline) and strong winds may add some excitement for you. Once at the top, the views on both sides make the climb worthwhile and you will definitely want to bring a camera to record your journey. It is about 12 miles from Kenosha to the top, and may take about 3 hours depending on your ability. Technically, this section was not that hard.
The backside of the pass is where things start to get interesting. Once off the pass, you will immediately hit some great singletrack downhill and the climb up is forgotten. However, after a few miles you will run into some rocky sections of large boulders in the trail that will probably slow you down quite a bit. Roots are quite common in this section as well...and can also take their toll. We ran out of water (we carry 3L Camelbaks) about 6 miles below the pass, so make sure you take a water filter out there!
The CO Trail has been re-routed in one key place, and instead of following the road down for almost the entire length of the trail (as it appears on older maps), it now has a significant climb added in. If you have an up-to-date map, you will see this climb about 10-12 miles down from Georgia Pass. Be prepared as it is about 1000' over 1.5 miles and was quite difficult after having ridden in high altitude and having about 22 miles of trail behind us. It is a long steady climb to be sure, and you will be cursing the CO Trail folks for adding this section in...until you start going down again. This is some of the best singletrack you will encounter on the CO Trail anywhere from this point back to Denver. From the top of this ascent, almost all the way to Hwy 9, there are fantastic descents, easy and scenic forest sections, and just a few short climbs thrown in to keep you honest. Just great riding for the last 10 or so miles.
Once into Breckenridge, it is about a 4 mile ride up the bike path (south) until you get into the business part of town. You can ride to wherever you arranged to meet your friends. Have a nice meal, then jump in the car, head back to Kenosha (approx. 1 hour by car) to get your other vehicle, and call it a day. It took us about 8 hours to do the 32 trail miles...but we had some rain which made things extra slick and slow in a few places. A good weather day might cut that time somewhat. As with most any trail, you will want to bring a good map with you (we used the Latitude 40, Summit County Trails map).