Hi Nadine,
Roughly, Avalanche lake sits between Colden and Algonquin, Though more specifically, It really sits between Colden and Avalanche Mountain, which is a smaller mountain that is part of the Algonqiun massif.
Avalanche Pass starts on the approach to the lake, perhaps as much as a 1/2 mile or so before the lake, about 3/4 of a mile past Avlanche Camp. The pass becomes very narrow before finally opening up to Avalanche lake. this is a wonderful place to visit - especially in the winter when you can walk out on the lake and drink in the views that you cannot see in the summer as you cling to the "Hitch Up Matildas" (boardwalks along the sides of the cliffs)
- However, Hurricane Andrew or Floyd (I can never get them straight) in 1999 or 2000, devastated the area and caused a huge slide to come down, leaving tons of debris some 10-15 feet high - I think debris came down both sides, but it was heavier from the Colden side.
There has been a lot of trailwork in that area, and although the danger of an avalanche does exist, you are pretty safe, Though I do recall the DEC banishing skiing on the slide a year or so ago, due to possible avalanche conditions.
You are not talking of skiing the slide, but skiing the trail at the bottom of the slide (no danger there right?

)
I seriously wouldn't bother with avalanche gear, unless there was an unusually heavy significant snowfall within the few days preceding your trip. Most people I know that have skiied or snowshoed through there have never even given it a second thought, though the Wright avalanche a few years back did raise an awareenss of the possibilty of an avalanche in the Adirondacks. Many folks do this annually - in and back. (Coming back down Misery mile is even better!!)
You can always call the NYSDEC in Raybrook for any latest avalanche advisories.
As far as gear, If I recall from an earlier post, you have quite an arsenal of skis and boots (Was it the the Scarpa T-2's or 4's that you like very much? I am still a leatherboot)
If it were me, I'd bring my Voile 3-pin cable bindings and 1.5 camber metal edge Karhu XCD's (older telemark ski) rather than my lighter setup. (sigh.....Yeah, I know some would think my "heavier" setup is a "Lighter" setup)
Since I don't remember what you ski, I can tell you a bit about the terrain -
The first 2 miles into Marcy dam is just mild ups and downs - Rolling terrain - I wear my skins - Others just apply grip wax well outside the pocket and go.
From Marcy Dam to Avalanche Camp, I don't think the trail rises more than around 500-650 feet over ~ 2 miles - After that, the next mile to Avalanche pass is the steepest - The trail rises around 6-700 feet over that last mile before leveling out at the lake.
As long as you are there, You might want to consider skiing up the Whiteface auto road the next day - Bring crampons for the last 200 feet to the top, it makes a great trip.
Into MArcy Dam, You'll probably find folks skiing on all kinds of stuff out there
I hope this helps you - Others will probably add more significant thoughts
Hope you have a great trip
Rick