(WINTER) HOLD ON! If you don't have much high-elevation, winter climbing experience, be careful in your planning and take a partner. Even the "easy" 14ers (Quandary, Sherman, Grays & Torreys) can be deadly in winter.
Take Colorado 17 to the town of Moffat. On the south side of town, look for a sign for the turn to Crestone. Turn east on the "RD T" road. You will soon see a Forest Service sign that says 15 miles to the South Crestone trailhead. Drive 11.4 miles to a road junction. Keep left and follow the main road into Crestone. In Crestone, turn right (east) onto Galena Street and the road will turn to 2WD dirt, with approx. 2 miles to go. When the road enters National Forest, it is labeled as the "South Crestone Road 949" and becomes more difficult but good-clearance vehicles should be able to make it to the end.
Leave the trailhead and follow the trail for a couple hundred feet to a trail junction - Photo #1. Turn right and follow the Willow Creek trail into the forest and across 2 small streams. After a short distance, exit the forest, turn left, and continue up through a clearing - Photo #2. Follow the solid trail back into the forest and up a bunch of large switchbacks. After over 1.25 miles from the trailhead, exit the forest on a small hill (9,900') where much of the remaining route can be seen to the east - Photo #3. Taken from the same location, Photo #4 is a closer look at some of the route, over 2 miles ahead.
Descend a bit, continue through semi-open terrain, and then follow the trail east back into the forest. Above 10,000', there are several areas of switchbacks - Photo #5. Keep grinding east and northeast up through the forest to 10,400' where the trail begins to curve right (southeast) and crosses an easy section of rock slabs - Photo #6. Taken from this general location, Photo #7 looks southeast at the headwall you must cross/climb to reach the upper basin and Willow Lake. Near 10,900', cross the Willow Creek stream (Photo #8) and follow the trail as it switchbacks southeast up the headwall. Exit the trees near 11,100' and climb the final switchbacks (Photo #9) to reach the top of the headwall - Photo #10.
On flatter terrain, pass a small boulder field (Photo #11) and re-enter the forest. Hike a short distance to reach another stream crossing - Photo #12. Cross back to the north side of the creek and continue on the trail toward Willow Lake. From the stream crossing, it's approximately 3/4 mile to the lake. Hike through open areas (Photo #13) and forest as you approach the Willow Lake area. Potential camp sites start to appear within the last 1/2 mile to the lake, but most are closer. Just prior to the lake, pass a waterfall (Photo #14) and then hike up through a short, steep section of rock near some large boulders - Photo #15 and Photo #16. After ascending through the rocky area, hike a short distance through the forest (Photo #17) to Willow Lake - Photo #18. There are many social trails near the lake, so it's best to locate the main trail and where it passes the lake, in daylight. The entire east end of the lake has 200' cliffs with a waterfall - Photo #18 and Photo #19.
From the west end of the lake, the main trail continues east along the shore, through willows, and then northeast up the hillside to gain the top of the cliffs. Photo #20 looks back down on the lake from 11,800' and Photo #21 was taken near the top of the waterfall.