There are two possible trailhead/approaches to climb this summit - one from the east side of Independence Pass, the other from the west side. We climbed it from the west side.
From the Town of Aspen, drive east up state highway 82 toward Independence Pass. A little past the Grottos TH, turn south (right) and drive down to the Lincoln Gulch Campground. If in a passenger car, you'll need to park here. 4WD or vehicles with better ground clearance may then continue ESE for Grizzly Reservoir. This road is identified as CR23 or FS107. Along the first 3 miles to the New York TH, there are numerous, designated, primitive campsites. The road tends to be slow going with potholes, etc., but no real major obstacles. It may take over a half hour to drive the 6 plus miles back to the reservoir. There is a small campground there with facilities called the "Portal" campground.
Just past the campground, in prior years, we have found a locked gate across the road as it continues south up the valley. Because there are some private holdings further up valley, we've seen some persons with a key to that gate. We've seen the Forest Service keep that gate closed past the 4th of July weekend, depending on snow melt conditions. The gate may also be closed again in early fall. If the gate is open and you have good 4WD clearance, you may continue to drive up valley as far as "Ruby," and the Ruby Mine, right around, 11,400 ft. If the gate is closed, be prepared to walk an extra 4 miles, or do as we did one time , and bring mountain bikes and ride up the road to Ruby. The bikes won't seem much faster than walking when going uphill, but will speed your return to the campground considerably.
As mentioned before, this same summit can be approached from the east side of Independence Pass. From HWY 24 between Leadville and Buena Vista, turn west onto HWY82 and drive 14.5 miles to the turnoff for the South Fork of Lake Creek (FS391 as discussed for the other UN13,460 or Sayres BM.) Cross the Lake Fork on a new bridge and drive back as far as the turnoff on FS391 for Sayres Gulch. Shortly after that intersection, the main road becomes more 4WD. Continue by foot or 4WD up the South Fork and then turn up the old road into Peekaboo Gulch until stopped by either the Wilderness Boundary or deteriorating road conditions. If coming from this direction, UN13,460 would combine easily with Middle Mountain; #327 - "Prize BM;" and #381 - "Booby Prize." Check out the Pieplant quad for details.
There is a designated forest service campground with facilities but no drinking water at Lincoln Gulch. Beyond there are many designated primitive sites that receive heavy summer weekend use and often fill completely. Then at Grizzly Reservoir, there's another small campground with toilets but no drinking water. This is called "The Portal" CG.