You gotta be sure about those water sources, though. Hiking along the upper Green River in Wyoming's Wind Rivers, I hit a 5 mile stretch with no water sources except the Green, which was full of glacial silt (what gives it its color up there) and would have clogged my filter in a hurry.. It was a quite warm day, too. Both the dog and I were really panting by the time we reached a small spring. Most of the time, though, you can be reasonably sure.
For the same weight as Jerry's pint bottle, I can take a 2 liter Evernew bottle. Platypus bottles weigh about the same as Evernew. Both roll up into a tiny space. That way if I do need more water (so I can camp away from water sources when backpacking), I have a place to put it.
Packing your fears, rather than a reasonable risk assessment, leads to a lot of unnecessary stuff carried. The Columbia ain't gonna dry up, although with the amount of agricultural chemicals and other goodies in it, I wouldn't want to drink it!
On the other hand, I never go without rain gear. If it doesn't rain, there is often waist-high brush (inevitably thorns or stinging nettles) soggy with deaf to wade through, or a cold, windy, exposed area up high where I really want a hard shell head to foot to keep warm, especially when stopped to admire the view (something I do more and more as I get older
).
