All the beta for the approach is in Alex's and Jason's guidebook that came out about 3 years ago or so. I've been in there plenty of times myself when I used to live in Yakivegas, and there are really only three ways to go in and not spend a day in the doing, depending upon which end of the cliff you want to end up at.
Read about it here.
With the snow the way it is now, AlpineMonkey has the timeline down... it's about three hours one way on foot. And I've always gone in on foot. Sometimes skis, sometimes snowsoes, sometimes I just booted it in. Depends. If you're headed to the Septum/Split Rock Camp area, take skis, cuz you can rip it up for a little ways from the cliff base down to the trail that leads to the beaver dam crossing. Then when you hit the road, put 'em back on, and you're down in minutes!