Start putting your spare change in a large jar and go with one of these or do the cheap PVC pipe:
http://www.landmarkflyrodtubes.com/Tubes/aluminum.htm
I don't know anyone, who is a serious Fly Fishing Trekker, that does not use a rod tube while hiking in the Sierras...one major fall and a busted rod results...
Those mountains are not real forgiving...
PT/TB