The Beaver Lake Trail follows Beaver Creek, never far from it, for about 6 miles to Turqoise Lake. From there, the route gains the Mount Jackson northeast ridge, and follows the ridge to the summit. Other routes might finish on the same ridge.
Without any detours or side trips, you should be able to limit the round trip distance on this trip to 20 miles.
Getting There - ApproachExit Interstate-70 at Avon, and follow the main road about 3 miles south to the Beaver Creek Ski Resort complex. Pick up a parking permit at the guard station as you enter the resort. Parking is free in the summer but not in the winter. As you drive up through the resort community, ignore the "All Public Parking" sign and drive a quarter mile farther to the actual last public parking garage. You want to park as close to the trailhead as possible, which is not very close. The closest parking to the trailhead is called Village Hall.
Find your way out of the parking garage and the maze of buildings to the base of chair lift 6. Pick up the Five Senses Trail alongside the main road going up. The Five Senses Trail becomes the Beaver Lake Trail after a half mile or so. The trail signage is excellent. Cross Beaver Creek on a good bridge and proceed about 3 miles to the Holy Cross Wilderness boundary. Beaver Lake is just a little further.
Continue past Beaver Lake for another 3 miles, almost to the lower Turqoise Lake. If you are backpacking, you will probably set up camp between these two lakes, or right at Turqoise Lake. Beaver Lake is closed to campers.
RouteWatch for a fork in the trail just below lower Turqoise Lake -- before you actually reach the lake. The fork is marked with a small sign on your left. Take the Grouse Mountain Trail. Follow this trail just until you pop out of the trees. Then leave the trail, turning south toward the saddle on the long ridge connecting Mount Jackson with Grouse Mountain. You may pick up a small trail leading up to the saddle. The Holy Cross Ridge, Mount of the Holy Cross, and the rest of the Sawatch Range come into view all at once when you reach the saddle. However, you can't see the Mount Jackson summit from there. The saddle is approximately 12,000' elevation.
The ridge is wide and fairly flat but drops off sharply at the edges. From here you can see the Turqoise Lakes that you missed on the way up. Climb west and south up the ridge. Eventually the summit comes into view. The final half mile of the ridge sharpens a bit. Some scrambling is required to skirt the main obstacle on the ridge. Stay to the left (east) side.
Soon you are standing on the summit of Mount Jackson. Enjoy the view!