Tumalo Falls is a high volume waterfall west of Bend, Oregon. Occasionally ice forms on it's sides. It takes a VERY cold spell for this to happen. For a gauge of what it takes to get something climbable see pics below. There are other ice possibilities in the area. Just to the right of the main flow is a small drip that forms a good mixed climb.
In nearby Redmond it was an average temp. of 12deg F for the prior four days.
prior 3 days average temp in Redmond was 21F.
Bend is located in Central Oregon. From bend you want to head out Skyliners road. Drive Skyliners for about 11 miles you should cross a bridge and then hit gravel this will be rd 4603. In the winter this last 2 miles is closed. The approach is very popular with xc skiers and snowshoers. No snowmobiles.
Top rope from above on either side of the main falls or the small drip on the climbers right. I'm not sure if these routes have been lead. If they have It would have been quite rare.
I'd recommend some long slings (maybe 30) for setting up the top rope.