Mt Sir Alexander doesn't see a lot of ascents even though it is a striking peak. This is likely a result of it not being an 11,000er as well as being somewhat off the beaten path. All of the more recent ascents I'm aware of have been by locals as it seems visitors from further afield are more intent on Mt Robson.
The east ridge(left skyline in the picture)was climbed by Bryce Cox and Sean Fraser approximately 10yrs ago. I think this was the FRA of this route. I can't remember if it was a winter or early spring ascent but the conditions were certainly wintery with temps in the minus 30C range. Approach was made using snowmobile and skis.
The north ridge is also a route but probably hasn't seen an ascent in a very long time. I wouldn't be surprised if it actually hasn't seen a second ascent.
I think most ascents are from the SW side.