If you fish the Ausable stick to the West Branch. Be sure you have a dependable wading staff as it has some of the most slippery rock bottom I have ever run into. There is a 5 mile stretch of C&R and just this year another 1.5 miles was made C&R from the Whiteface ski area to the bridge at the Hungry Trout Restaurant and Motel and Fly Shop. You should eat there at least once during your stay. There are 3 major fly shops on the river. Kevins shop at the Wilmington Bridge, The one at the Hungry Trout and , a must visit, Fran Betters Adirondack Sportsman Shop.
Like everything else early morning or the hour B4 dark is the best fishing on top. Nymph all day long thru the pocket water. I fish about 20 days a year up there. If weather is cloudy and a lit rain fish small olives....Good luck and watch your wading.....Bob