Take Castle Creek from the roundabout just west of the center of Aspen. Drive 12.5 miles (paved) to the Castle Creek trailhead. To the right, Forest Road (FR) 102 continues all all the way to 12,800'. Good-clearance passenger cars can drive about 1 mile up this road to reach the dispersed camp sites along the road. If you want to shorten your hike by parking higher, you must have a 4WD vehicle with good clearance. From the lower trailhead parking area, proceed 1.3 miles to a river crossing. In spring and early summer, this crossing is a challenge for some 4WD vehicles. Continue another 1.7 miles up FR 102 to a junction. Left will take you up the nasty Pearl Pass 4WD road. Staying right will keep you on the Castle Creek 102 road. If you drove up this far, there are a few parking spots near the junction. The road gets worse as it ascends into Montezuma Basin all the way to 12,800'.
From the 2WD trailhead, drive or hike 1.3 miles to the stream crossing near 10,200' - Photo #1. If you cannot drive beyond this point, there is a footbridge on the left. Continue about 1.5 miles up the road to a bridge crossing. Follow the road less than 0.25 mile up a steep hill to reach a road junction near 11,150'. The Pearl Pass road starts on the left and FR 102 continues to the right. Stay right and continue for 2 miles up the road (Photo #2, Photo #3 and Photo #4) to 12,600' near the Montezuma Mine area. Continue on the road (Photo #5) for another 1/2 mile to the end at 12,800' before a small basin - Photo #6. From here, you are looking southwest at a headwall that has snow cover through much of the summer. When covered with snow, the easiest way to climb this headwall is to traverse across the left side of the basin and climb the left side of the slope. Some climbers choose to climb the right side, but it's slightly steeper. And the left side provides a more direct line to the upper route. Photo #7 and Photo #8 are closer looks at the area. Climb 500' up the headwall to reach the upper basin (13,400') between Castle Peak and Conundrum Peak
Castle's North Face is straight ahead and the North Face Couloir is on the left side of the face - Photo #9. Continue south across the basin toward the bottom of the couloir. Photo #10 looks back on the area. Photo #11 and Photo #12 show the North Face Couloir as you approach it from the basin. It may be easiest to hike toward the left side of the basin before angling into the bottom of the couloir. This may save some loss of elevation in the south end of the basin. Reach the base of the couloir below 13,600' (Photo #13) and start climbing south toward a saddle on the Northeast Ridge - Photo #14. The terrain is not that steep but should only be climbed with continuous, stable snow. As you climb the wide couloir, Castle's North Face is off to your right. Continue climbing (Photo #15, Photo #16 and Photo #17) to 14,000' where the couloir becomes slightly steeper (40 degrees max). Behind you, there are great views of Conundrum Peak - Photo #19. Continue for another 100' to reach the top of the couloir at a small saddle on the Northeast Ridge - Photo #20.
From the saddle (14,100'), turn right and climb the final pitch (Photo #21) on the Northeast Ridge Route, toward the summit. Shortly after leaving the saddle, there are a few rock sections that require delicate climbing when surrounded by snow - Photo #22. Climb the steep, final 100' of the ridge to reach the summit - Photo #23. From the summit, Photo #24 looks down over the couloir.
IMPORTANT: This route enters the Maroon Bells - Snowmass Wilderness area. Wilderness areas have special regulations and restrictions for party size, dispersed camping, campfires, etc. Also, dog owners should read the wilderness information carefully because some wilderness areas prohibit dogs to be off-leash and/or limit how close dogs can be to lakes and streams. If you have questions about the Wilderness area, please contact a U.S. Forest Service office for the National Forest(s) listed above.