How to Get Water on a Thru-Hike (The Actual Process, Start to Finish)

One of the most common questions I get from people who've never done a long trail before is some version of: "But… how do you get water?" Fair question. Here's exactly how I do it.

Step 1: Find a Water Source

In FarOut Water sources look like this (the app has been updated since this screenshot was taken - it may look slightly different now):

In the AWOL PDF Guide they’ll look like this:

On most sections of the AT, water isn't hard to come by — I typically plan around getting water at camp, which keeps things simple. If I'm hiking more than 12 miles, or camping somewhere without a reliable source, I'll think ahead and carry more.

There are two main types of water sources on trail:

Springs are generally the better option. They're colder, cleaner, and less likely to carry sediment or bacteria. A lot of AT springs are piped — there'll be a metal or PVC pipe sticking out of a hillside near a shelter or campsite, and you just hold your bag under it. Easy.

Streams are more common and totally fine, but they're open to the environment — leaves, bugs, dirt, runoff — so they tend to be murkier and require a little more filtering attention.

Finding water on the map: I use FarOut (formerly Guthook) for water planning. Water sources are marked with a droplet icon, and you can tap into the comments on any campsite to see if other hikers have noted a nearby source that isn't officially marked. Crowdsourced info on FarOut is genuinely useful — people leave notes like "spring was flowing strong" or "this one was dry in September."

One thing to know about out West: Water sources are much more spread out on trails like the PCT and CDT. You'll sometimes go 20+ miles between sources. Planning your water carries carefully — and yes, sometimes using chemical treatment for sketchy sources — is a bigger part of the game out there than it is on the AT.

Step 2: Collect Your "Dirty" Water

"Dirty" just means unfiltered — it's the term we use for water that hasn't been treated yet. Most of it isn't actually that dirty.

I collect dirty water in the Sawyer squeeze bags that come with my filter. I've tried other bags — including the CNOC Vecto (pictured above), which a lot of people swear by — but I keep coming back to Sawyer's own bags. Here's why: aftermarket bags, including the CNOC, can develop pinhole leaks over time. The problem is you often won't notice until you've been slowly losing water for miles and can't figure out why your bag feels light. Sawyer's bags are more durable in my experience, and I can tell when they're starting to degrade and need replacing. That peace of mind is worth more to me than a nicer fill opening.

Springs with pipes are the easiest fill — just hold the bag under the flow. Streams are trickier; you're often scooping at weird angles in shallow water. A wider-mouthed dirty bag helps a lot here.

Step 3: Filter Your Water

This is an older photo from my first ever water filter setup: A Sawyer Squeeze and a CNOC bag (I don’t prefer either anymore).

I use a Sawyer Micro Squeeze as my main filter. It's the lightest in the Sawyer lineup at 2 oz, rated to 100,000 gallons, and screws directly onto Sawyer's squeeze bags and standard 28mm bottles (including SmartWater). My clean water lives in SmartWater bottles — lightweight, durable, easy to find replacements for at gas stations and hostels, and compatible with every squeeze filter on the market.

My water filtering setup in 2026:

• Screw the Micro Squeeze onto the dirty bag
• Add the blue coupler ring to the output side
• Loosely attach a SmartWater bottle to the other end of the coupler ring (loose is key — too tight and you create a vacuum and nothing flows)
• Brace the bottle between feet for stability
• Squeeze gently and roll the bag as you go to move the dirty water through the filter and into your water bottle

I usually filter at camp, near my tent or at the shelter. But there are two situations where I filter at the source instead:

Cold weather: Hollow fiber filters — Sawyer included — will freeze and become useless if left out in the cold. If temps are dropping, I filter at the source, then immediately tuck the filter inside my jacket so my body heat keeps it warm. At night it goes in my sleeping bag with me. This isn't optional — a frozen filter is a ruined filter.

Cameling up: If I know there's a long dry stretch ahead, I'll filter everything at the source, fill all my bottles, and carry the extra weight. Better than running out.

Dinner or Lunch: If there’s a water source within 2 hours of camp and it’s late enough in the day, I’ll stop to make and eat dinner and by the water source. This saves me carrying 1 liter to camp, allows me to really use my most caloric meal of the day, and makes me happy. Heck, sometimes I cook and eat my dinner for lunch by a water source and just snack when I get to camp instead.

What About Chemical Treatment?

I carry Aquamira as a backup, but honestly I've never had to use it on the AT. Still-standing or stagnant water is where chemical treatment earns its keep — hollow fiber filters catch particles and most microbes, but they don't cover everything a sketchy puddle might throw at you. Out West, where water sources are sometimes pretty grim, chemical treatment is more of a real consideration. On the AT, I've never needed it.

The Full Picture

On a typical day I go through at least 3 liters, more in heat or on big mileage days. The whole system — Sawyer Micro, SmartWater bottles, Sawyer bags — is lightweight, reliable, and cheap to replace pieces of when something wears out.