Personal water filters that can be easily carried on your person for back country use.
I have two. One is a MSR Mini Works that I carry while on the move and is or was issued by the USMC, and the other is a Katadyn Base Camp when staying put in one place for periods of time longer than a night or two. The MSR is a ceramic filtered manual pump filter slightly taller than a pop can. It filters everything down to viruses.
The Katadyn Base Camp is basically a 2.5 - 3gal bag that utilizes the Katadyn Hiker Pro filter cartridge in the bottom and works on gravity. It filters everything except viruses. Fill it, hang it and let gravity do the work. I also have a 5-liter MSR water bladder that I fill up and use to stay ahead of the Katadyn if there are multiple users. Both filters produce about 1 liter of filtered water/minute. I've never noticed any excessive time to fill a 40 or 48oz water bottle. BTW, the MSR screws onto standard water bottles, the MSR water bladder, Camelbacks and other brands of hydration systems for filling. The Katadyn Base Camp seems to work faster if hung higher and with longer tubes attached. When stowed, both take up little room and add little weight to a pack. For the most part we aren't hiking any distance anyway and use ATVs or boats of one flavor or another when on the move.
The Katadyn filter can be sterilized for reuse by boiling it, but it should be changed after 200 liters anyway. Normally, I just toss it when I'm done using it and replace it with another before the next outing. I also carry a spare when oot and aboot especially in moose camp which can be a few days or up to 3-weeks. The MSR filter is cleaned by a Scotch pad and boiling after use. Using the scratchy pad takes ceramic material off off the filter element and MSR supplies a plastic gauge to determine when enough material is scratched away warranting replacement. Theoretically, the MSR should filter about 10k liters - depending on raw water quality - before wearing down enough to require replacement.
I also carry chorine dioxide tablets for the Katadyn in the event I suspect there may be viruses in the raw water supply. I've never used them in the years I've been using the Katadyn other than throwing one in the 5-liter MSR bladder as a precaution to keep the water stored in it from getting yukky. For proper treatment, use on tab per liter. I think I see a Steri-Pen in my future too.
Most of the concerns in AK are giardia and other bugs and bacteria. Viruses are pretty fragile in the outdoors and I would imagine are rarely present unless downstream from a garbage dump or sewerage plant.