Taken from near the town of Crestone, Photo #1 is a look at Challenger from the west. First, follow the Willow Creek Approach to Willow Lake. If you are camping, there are campsites below the lake.
Due to social trails, the main trail can be hard to follow near the west end of the lake - Photo #2. Plus, the lake can be difficult to see until you are near the shore. Once you are near the lake, follow the trail as it parallels the north side of the lake. Leave the trees and continue through thick willows along the shore - Photo #3. Your next goal is to gain the cliffs/headwall on the east end of the lake. Before reaching the cliffs, turn left and climb north up the hillside - Photo #4. Climb 150' up the hillside, turn right and follow the trail to the top of the cliffs (11,800') - Photo #5. Photo #6 looks down on over Willow Lakes from the top of the headwall. Cross the stream above the waterfall (Photo #7) and follow cairns and trail segments across the remainder of this flat area - Photo #8. Above 11,800', continue below some rocks and through willows (Photo #9 and Photo #10),
Shortly after exiting the willows, reach the base of the North Slope (Photo #11) near 11,900'. Locate a small trail that begins the ascent up the grassy slope. As seen in Photo #12, the route climbs up to the left side of a large rock "rib" and then continues south up through more difficult terrain (Photo #13) to the right of a large gully that stretches to the summit ridge. Begin hiking southwest up the grassy slope.
Note: The remainder of this route uses the traditional ("standard") route up the slope. In recent years, some people have climbed to the right of this area to hit the summit ridge further to the northwest. That variation is a bit more solid, but steeper and more difficult. The remainder of this description sticks to the traditional route.
After about 500' of elevation gain, you will reach the rock rib - Photo #14. Stay near the rib and continue up the slope as the terrain starts to get steeper - Photo #15. Photo #16 is a view of the more difficult terrain ahead. Near 13,200', reach the upper portion of the rib - Photo #17 and Photo #18. Turn left a bit and traverse south up the slope toward more difficult terrain - Photo #19. Weave up through rock slabs and grass to 13,300' and talus-covered terrain - Photo #20. The remaining 600' to the ridge is the most difficult portion of the route because the terrain is steep and loose, and route finding can be time consuming. Look for cairns and trail segments as you weave up through the rocks. The key is to stay off to the right of the gully (Photo #19) and get closer to the gully as you get closer to the ridge. To save time, you may have to do some easy Class 3 scrambling. Even if you keep the difficulty at Class 2, you will encounter loose rock on this slope, but it's still the easiest way to the top. The steepest portion of the slope is between 13,400' and 13,700' - Photo #21.
When you reach the upper portion of the slope (Photo #22 and Photo #23), look for a good line that will gradually lead you closer to the top of the gully. Just below the ridge, follow a dirt trail that leads up to a notch in the ridge - Photo #24 and Photo #25. Photo #26 looks down on the area. Pass through the notch (Photo #27 and Photo #28), turn left (Photo #29) and climb up to the ridge crest - Photo #30.
Follow the ridge southeast (Photo #31 and Photo #32) toward the summit. Portions of the ridge become narrow and some people may find it more comfortable to drop a few feet to the left to avoid the mild exposure. The last 0.1 mile before the summit becomes more steep (Photo #33) as you gain a bump just below the summit. Continue over to the top - Photo #34. Photo #35 looks east to Kit Carson Peak and The Crestones.