Five Things I Wish I Knew Before Backpacking the Three Sisters Loop

In August 2019 we set out to hike the loop around three of Oregon’s prettiest peaks in the Cascade Range (South Sister, Middle Sister, and North Sister), collectively called the Three Sisters. The Three Sisters Loop is an epic 50-mile trek through Deschutes and Willamette National Forests that highlights central Oregon’s incredibly scenic and diverse landscape.

We planned to hike at a leisurely pace, hiking approximately 10-miles a day for five days. This was my first-time hiking in Oregon and I was in awe of the lava rock, glaciers, and volcanoes that we saw along our trip. Despite all of our planning there’s bound to be some surprises.

Here are five things I wish I had known before backpacking the Three Sisters Loop.

1. Afternoon thunderstorms are common

When we left Bend, Oregon there was a heatwave and temperatures were hovering close to 100 degrees. It was hot with no rain in the forecast. We packed our rain jackets just to be safe, and boy were we glad we did! On our first day of hiking we noticed the dark clouds starting to move in. By 2pm it was clear that we needed to set up camp immediately because a storm was approaching quickly.

We found a campsite and shortly after setting up the tents we were hit with hail, thunder, and lightning. The storm raged for about an hour. When we emerged from our tents it was clear that this was just a brief reprieve, and that there was more rain and hail to come. We quickly made dinner and were able to store our food (using bear canisters and hanging since this is bear country) before the second part of the storm moved through.

The peaks of the Three Sisters are all over 10,000 feet, but the trail that circles the Three Sisters Wilderness sits at about 6,500 feet of elevation. I didn’t expect thunderstorms to be an issue at this elevation, or on the eastern side of the mountain range. Boy was I surprised! Every afternoon we watched the clouds move in. Luckily, the first day was the only big storm.

2. Mosquitoes are a nuisance, even in August

Bring lots of DEET because the mosquitoes are relentless! Silly me thought that the volcanic rock meant that there wouldn’t be mosquitoes. But mosquitoes thrive anywhere that there is, or ever was, water.

Some of our most scenic campsites had the worst mosquitoes. Bring a headnet and try to eat dinner early or late as the mosquitoes come out in full force around sunset.

3. Water is scarce

If you look at a map of the Three Sisters Wilderness it looks like there are streams everywhere! I didn’t anticipate that many of the water sources would be dry in early August of a high snow year. Just because a stream is marked on the map doesn’t mean it is a good water source- some of the streams that weren’t dry were running with glacial water, thick with sediment and sure to clog your filter.

Based on the number of very thirsty hikers we passed, I wasn’t the only one caught by surprise. Be prepared with extra Platypus bags or some spare dirty bags for your water filter because you might need to carry more water than you usually do. Depending on your itinerary, you might even need to dry camp somewhere along the route. This map of the reliable water sources on the trail will help you plan your adventure.

4. The burn zones are extensive

The Three Sisters Wilderness has suffered several large wildfires and the forest is still trying to recover.

In 2012, the Pole Creek fire charred 41 square miles on the eastern side of the mountain. This area was marked on my map, but I wasn’t prepared for the extent of damage. When you are hiking on the east side of the trail it is very difficult to plan around the burn zone. Some hikers choose to start the loop from the Pole Creek Trailhead to break up the burn zone. But hikers who start from one of the other trailheads are forced to do big miles or camp within the burn zone (usually near Alder Creek or the junction with Camp Lake).

On the west side of the loop, the Horse Creek Complex fire burned over 28,000 acres of the Willamette National Forest in August 2017. While the fire damage isn’t as extensive as the Pole Creek burn zone it is still shocking. Plus, since the fire was fairly recent the burn zone wasn’t included on our map, and it was a total surprise! It is easy to avoid camping within the burn zone on the west side of the loop, but you should be prepared for extremely dusty trails, lots of soot lingering on the trees, and the possibility of falling trees.

5. Summer temperatures are in the 80s and 90s

Scorching temperatures, lack of shade in the burn zones, and a shortage of water can make some hiking days pretty miserable, and potentially dangerous. We may have been hiking during a heat wave, but after reading trip reports on other blogs it seems that soaring summer temperatures is the new normal.

Bring a hat with a wide brim and plenty of sunblock to help protect your skin from sunburn. I also hiked in a lightweight long sleeve shirt to protect my sensitive skin (it also helped with the mosquitoes!). Be prepared to carry more water than you normally would so you can stay hydrated in the heat.

Plan your own adventure