I still haven't had an Ames Lager and have given up actively looking long ago. I've been able to get all the other ISU beers in Cedar Falls and I'm sure I'll be able to get the new Back Pocket brew. Last time I asked for it, the beer guy thought the Trice Legacy was what I was looking for.
Don't give up. You asking may be what brings it to some stores.
However, if you make it to Ames, let me know and I'll make sure you get some. I always have a few cases in our basement fridge.