Tantalus is a rugged, glaciated peak clearly visible from the highway between Squamish and Whistler. Approaching on foot means starting essentially at sea-level and so many ascents begin with the assistance of a helicopter.
The traverse as described starts from the Sigurd Creek trailhead and climbs over a high shoulder below the summit of Mt. Pelion before dropping down to the col separating Pelion from Tantalus. There are a few options for starting the North Ridge. It is possible to climb the initial buttress of the ridge directly at low 5th class. However, Eric and I climbed steep snow right of the crest to a notch that leads onto a glacier on the west side of the ridge, from which we gained the ridge proper. The ridge itself is mostly enjoyable 4th class climbing overlooking the spectacular Rumbling Glacier.
From the summit, a mixture of downclimbing and rappelling (we made 4 x 30 metre rappels) down the Southeast Face gains the steep snowslope below Mt. Dione. Crossing the shrund and getting onto the snow was likely the crux of the traverse. From the shoulder below Dione, descend a couloir to the Dione Glacier which is then traversed to the Haberl Hut. From here, traverse to the Serratus-Ionia col, make a somewhat tricky descent to the Russian Army camp flats and pick up the trail that leads down to Lake Lovelywater and then down to the river. We stopped our watches when we reached the cable car.
This is the "light" version of the Tantalus Traverse. The full "Tantalus Enchainment" involves adding the summits of Dione, Serratus and Alpha. Lots of possibilities for traverses and linkups exist in the Tantalus Range and indeed many have likely been done by people such as Peter Croft and Marc-Andre Leclerc, both of whom spent time in the Tantalus.