All of the five 13er summits that we have placed in the Buckskin Pass Group can be accessed as a day-hike from the Maroon Lake TH. It is possible to also backpack up Minnehaha Creek and set up a base camp from which all five summits could easily be done in about two days. UN13,336 we have sequenced with UN13,020 for a fairly long day-hike from Maroon Lake.
From the Maroon Lake parking area, head south on the Crater Lake trail #1975. Make sure you don't get diverted over onto the scenic Maroon Lake trail. Walk 1.5 miles to Crater Lake amid hordes of dayhikers, touroids, etc., unless you've gotten a good early start. View the "Deadly Bells" warning sign. If you're going to backpack in and camp overnight, you'll also need to self-register. At Crater Lake, turn west and head up Trail #1978 toward Buckskin Pass. This trail heads up Minnehaha Gulch and begins to gain some serious altitude shortly after Crater Lake. There are/were some backpacking campsites near the lake and the trail intersection. At about 11,100 ft., there are/were some excellent campsites on the ridge to the right above the trail if camping overnight. They are located a short distance before the trail crosses Minnehaha Creek at 11,060 ft. It's about 3 miles to this location. Be sure and check recent regulations regarding backcountry camping in this area in case a designated site system has been implemented.
From where the trail crosses over Minnehahah Creek, continue a little farther toward Buckskin Pass, but watch for the trail intersection where you turn north to head over Willow Pass at 12,580 ft. Most all of the hiking above treeline is through tundra, but the final gain to the pass will be through the typical maroon sedimentary rock. On the north side of the pass, drop down on a few switchbacks into Willow Basin. The trail leads down to Willow Lake passing through a vast tundra basin dotted with maroon boulders and colorful orange lichen. Just below 12,000 feet in elevation, watch for a trail that heads off to the west. Follow this trail as it regains altitude to an unnamed pass that we will call East Snowmass Creek Pass. The trail passes through some of the white rock rubble that characterizes UN13,020 which will be just left of the trail as you head up to the pass. UN13,336 will be visible the entire time you're crossing Willow Basin. It has a distinct, split personality geologically, with half of the peak comprised of the maroon, metamorphosed sedimentary mudstone, and the whitish, intrusive granite.
Once you gain the pass, you will be at a dividing line between the two major rock types. There is/was a post here to mark the trail as it heads down into East Snowmass Creek. In climbing 13ers, when given a choice, our rule was to always climb the highest summit first, so head north from the pass on soft maroon dirt and maroon rocks and scree.
Follow mostly on the west side of the ridge staying below the crest most of the time. We found this to be the easiest path. There are some small cliff bands lower down to work through, but nothing difficult. Higher up, you leave behind the maroon rock and get onto the broken, boulder rubble of the whitish rock. It becomes mostly just slugging it out with minor obstacles at various places to search around and overcome until you arrive at the summit. Along the way and on the summit, you'll enjoy a panoramic view of the Snowmass Mtn. massif and Snowmass Lake to the west. Capitol Peak is also in view. From here on out, even if you go on over to UN13,020, you'll basically be working your way back to the beginning of the hike at Maroon Lake.
Links to other information, routes & trip reports for this peak that may be helpful.