I read where the Avalanche quest comes from Sunbrand as a side quest, along with Ivan soulsinger,Avalanche is not on my map but Greystone is. I may have to get game to look at this because Sunbrand has nothing for me. I dont recall if the book is in Greystones and he is also on my map, or the book is in Avalanches, because I completed the book quest. Oh well, If you know anything I might have done wrong let me know.
Sunbrand gives the "Soul Winger" quest, which sends you to Avalanche.
Avalanche is in the Skythorn Tower in the Drake Hatchery. That tower is the rightmost of the two you see up in the northeast corner of the map. You can use your quest arrow (CTRL+T) to get there. This arrow can be deceptive, because there are two towers there next to each other, but the entrances to the towers aren't next to each other. You have to go up and around the walkway circle to get from the leftmost entrance to the rightmost entrance, where Avalanche is.