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The Three Sisters Wilderness Area
Obsidian Basin - Opie Dilldock Pass - Collier Cone - Scott Springs - Obsidian Falls
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Length: 16 miles round trip
Elevation Change: c. 2800' cumulative elevation gain
Season: Summer thru Fall
Difficulty:   Difficult
NW Forest Pass Required

Please note that you need a Special Use Permit to hike this loop or anywhere in the Obsidian Cliffs area. Contact the local Forest Ranger Station for such a permit.

Features: First, let me say, that considering the configuration of this hike, one does not have to do the entire loop to enjoy a fabulous hiking experience to any part of this area.

I hiked the loop clockwise and did a couple side trips, such as the 4 in one Cones. The trail is remarkably gentle, just long if you do the whole thing. I've been to this area a couple of times, and the first time I only went to Opie Dilldock Pass. I can guarantee you a fabulous hike if you only go this far.

With the exception of a brief view point at about 1.5 miles, the first 3 miles of this hike is entirely in a dense forest. Not until about 3 miles does the trail break out due to the extensive lava flows. Even then, the trail is in and out the forest.

At about 4 miles the trail is out in the open crossing an extensive cinder field and the cutoff trail to the top of 4 in One Cones is clearly marked. This side trip is definitely worth it if you have the time. Not only are you afforded remarkable views of the North and Middle Sisters Mountains, but looking north you can see Mt Washington, Three Fingered Jack, Mt Jefferson, and even Mt Hood.

The next mile is a bit steeper and the trail then connects to the Pacific Crest Trail in a nice meadow area. Depending on the time of year you get there, flowers can be plentiful. I imagine the flying insects can be too.

Heading south on the PCT the trail continues to climb. Soon the trail passes Minnie Scott Springs. This water source appears to be year round. The trail climbs through a short switchback then heads toward the base of Collier Cone.

A number of paths can be seen that will take you up Collier Cone, but the main path is after Opie Dilldock Pass. The loop trail around Collier Cone intersects the PCT just a few feet apart and are marked with rather substantial cairns.

Then the trail does a surprising steep drop through a series of short switchbacks in order to cross a stream at what is called Sawyer Bar. This crossing can be difficult depending on what time of year you try to cross it.

The trail continues to loose elevation for the next mile or so before climbing back up the junction of the Glacier Way cutoff trail. At this junction, you can follow a user trail up the stream toward the Middle Sister Mountain into a beautiful valley overflowing in wildflowers if you get there in late July.

Whether you stay on the PCT of follow the user trail, you will end up at the same place in about a half mile. At that common destination you will be standing on a literal mountain of obsidian. More obsidian that you can imagine. Truly a marvel of nature. Be sure to treat this area with great respect.

Shortly after the trail comes to a couple of small ponds. And just beyond the ponds are springs of clear cold water that just come up out of the earth. And shortly after this you will come to Obsidian Falls as the trail begins to descend to the junction that you will need to complete the loop.

At the junction bear right onto Trail #3528, the Obsidian Trail which will take you back to the highway where you began your trek. The trail is mostly downhill, but there are occassions when you climb just a bit before continuing your descent.

In a little over a mile and a half you will come to the junction of the Glacier Way cutoff trial that you passed earlier on the PCT. The trail crosses the creek and climbs a bit to get over a rather large lava flow. There will be numerous opportunities for great photos of the Sisters behind you as you decend, so be sure to look back over your shoulder.

Then the trail eventually desends into the dense forest and you will no longer have any view opportunites. About a mile before the end of the loop you will come to the junction of a trail to Spring Lake. When I hiked this there was no sign to the lake, but there was a sign and it was obviously the junction to the lake.

Another mile of forested desent and you will come to the parking area of the Obsidian trail head. From here you need to follow the gravel road to the main highway and walk along the road back to your vehicle.

Looking up at the Middle Sisten from the Obsidian Basin trail
Looking up at the Middle Sisten from the Obsidian Basin trail

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