Just catching up on conditions for the Tantalus after two trips in the last week based out of the Haberl Hut.
The most obvious thing to report would be the rapid onset of summer conditions. Clear nights are providing a mild recovery of the snow surface, but only light surface refreezing. Crampons on the early starts have been useful. Crevasses are beginning to open up and quickly as well as moats/shrunds opening rapidly. It was amazing to see how quick this happened in the 4 days between my two trips (last Monday to last Friday). The shrund in the Dione couloir is now way too big to cross, the moat on the SE face of Dione still has a good plug or two in it making it easy to cross. Access to Tantalus is still easy enough on a plug in the moat as well. The north face of Serratus is still in good shape, but some of the crevasses are opening up to be quite large requiring a bit more circuitous path.
On Saturday my partner Laurie Block and I ventured into some slightly undocumented terrain on the SW face. I've spent a few trips climbing the SW spur and Dehydrated on Dalwhinnie, and have known there was a 5.9 variation of sorts on the proper buttress, but we went in some untraveled variations more on the S face creating an enjoyable 8p climb up steep cracks with face holds at 5.10-. I'll just call it the SW Buttress as climbed by us and have attached a beta photo and description. Great fun, good protection except for the easier approach pitch. Awesome positions and exposure!
I have also attached a recommended approach/descent beta for Dione. All of the gully on the approach are prone to rock fall and can all be easily avoided with a more scenic, but also more time consuming ridge climb as shown by the photo and indicated in Alpine Select.