Looking east up Mayflower Gulch
This route is approximately 9 miles. It starts at the Mayflower Gulch trailhead, hiking up the road until you reach some old cabins.
Turn north, crossing Mayflower Creek and thrashing through the willows, then head up along the east side of Pacific Creek towards the Atlantic Ridge. There are traces of trail(s) in this area.
Heading up Atlantic Ridge
After you gain the Atlantic ridge, head east up to Atlantic. There is no clear trail up the Atlantic ridge and you may find some class 3 scrambling. Continue heading east until you reach the Altantic summit.
From Atlantic, head north to Pacific, passing the Pacific tarn. The tarn is just below and east of the saddle between Atlantic and Pacific.
Continue north and reach the summit of Pacific.
On top of Pacific
Start the descent by heading west, just below Pacific's summit and on the south side of the "notch". There are a few class 3+ moves as you manuever through the notch. Then descend the north ridge of Pacific, either along the ridge or just below it. Just before you reach the saddle between Pacific and Crystal, head southwest as the route descends into Humbug Gulch.
Looking back at Pacific from Humbug Gulch
Follow the stream (you may want to cross back and forth to avoid willows) until you reach the woods on the north side of the stream. Then continue through the woods along the stream and watch closely for a concrete structure in the stream bed around 11,250'. There is a wooden bridge just west of the concrete structure. Cross here and follow the road around the Mayflower Hill Ridge. When the road diverges, always take the lower road. It will eventually lead you to a concrete structure across Mayflower Creek. Cross here and head back to the parking lot.
Map of Route
Atlantic to Pacific via Mayflower and Humbug Gulches