Adam Wilcox posted the route:
The Mount Tripyramid Slide Loop is a hiking route that's commonly used to access the ranked 4,000 footer peaks of North (4,180') and Middle Tripyramid (4,140'). Starting from the Livermore Road parking area in Waterville Valley, the route follows Livermore Rd. (an old logging road) for a few relatively easy miles, then ascends up the North Slide (a granite slab exposed during a landslide) to the North Peak. From there, rough and technical footing leads over the summits of Middle and South Peaks before descending steeply down the steep and gravel-ey South Slide back to Livermore Road, which is taken back to the parking lot. By the book, the loop is 11 miles with 3,000 feet of elevation gain. The majority of the gain is concentrated into a small distance going very steeply up the North Slide. While the terrain arguably never reaches 3rd-class, I wouldn't recommend this route in anything but dry conditions, especially for faster trips.
My GPS track is here: www.movescount.com/moves/move18932008