These are some notes on the Three Sisters area and horseback riding & camping. Caution: these recollections are from memory as I could not find my own, marked map. The info is generally correct but some specifics may be in error. In most cases just follow your nose and you'll do OK.
The Northern Section The Pacific Crest Trail (PCT) to Opie Dilldock Pass is a very scenic ride traversing through black, chunky lava flows; pumice flats; and forest. There are very good views to the north and west for most of the ride. The areas near the lower lava fields, Yapoah Crater, Minnie Springs and Opie Dilldock Pass are the most interesting. Park the horses at Opie Dilldock and hike up to Collier Glacier View Point and Collier Cone for some of the most breathtaking views in the state.
The Old Scott Route and Obsidian Trail make for a long, but interesting ride through a mix of old growth timber, deep forest, and high, alpine views. The blind canyon as you approach Opie Dilldock Pass from the west is particularly interesting as is crossing the Jerry Lava Flow.
There are broad lava plateaus near Four In One Cone that invite cross country exploration. Water is scarce except for North and South Matthieu Lakes, Minnie Scott Springs and Yapoah Lake. Yapoah Lake has a user trail to it but I have not ever used it. I have heard that you can get stock into the lake on the user trail.
The Western Section Permits must be obtained to enter the Obsidian Falls area for overnight travel. It is a particularly beautiful area with shards of obsidian sparkling in the sun everywhere and great views of the mountains. The only good camping area on Glacier Creek was closed to overnight use due to heavy use when we went through in 1994.
The PCT between Obsidian Falls and Linton Meadows is all very high, exposed, and quite scenic.
Linton Meadows is a terrific place for horse camping with lots of feed and water. Optional side trips to Eileen Lake and Husband Lake are easily possible. The camp is quite scenic and quite worth the drop down into the meadow from the higher PCT. If you approach from the south consider taking the James Creek Shelter trail or going through Race Track Meadow on trail 3511 as the drop will be much gentler. Trail 3547 is quite the drop.
Race Track Meadow does not have water as I recall and feed is marginal. James Creek Shelter is a good spot for camping but very small so take care to keep it in good shape.
If you stay high on the PCT it is actually possible to cross over between Middle and South Sister via a climber's trail up Separation Creek. The side trail is hard to find as it begins in a small meadow. Just head up the draw of Separation Creek. The first part of this route is very pretty and well worth the visit. The climb up to the high pass is extremely steep but passible to stock, but barely. I only recommend this if you are an adventure rider and are willing to risk possible injury to you and your animals. We did it loaded with camping gear but I walked and held onto my horse's tail to help me climb up. It is that steep. You top out at Chambers Lakes and a world of rock and snow. Be prepared for rough going. You can camp at the high lakes but carry feed as there is almost none. From here you can cross over to the east side. It is a wild ride!
It is a pretty good climb up to Wickiup Plain on the PCT trail but well graded.
The Southern Section Wickiup Plain is a broad plateau that begs for cross country travel but be forewarned. There are those who will insist that you stay on the trail. Be sure to climb to the top of LeConte Crater and see the small pool on top. The Sisters Mirror Lake area is good for horse camping but the only water is from lakes. I have heard that the climb to Koosha Mountain is worth the trip for the views of South Sister. Quite a few loops can be taken from here as shown on the map. Most of the open areas are pumice flats and water is scarce.
Moraine Lake is very beautiful but it doesn't make for good horse camping as it is so heavily used by backpackers and climbers and feed is not plentiful. You will not be welcomed with open arms. But by all means go see it and have lunch there. Note a small user trail just east of Moraine Lake. There is a big depression below the trail where it crosses a lava flow. You would find good feed and as I recall there is a small creek running through it for water. This would be a better camp if you can find a spot hidden from view from the main trail.
Do not take the Hell Creek trail with stock. It has one of the longest steep stretches of trail that I have ever encountered. All of us had shin splints by the time we reached Devils Lake. The trail is signed "closed to stock" at the bottom but was not at the top when we tried it.
The Fall Creek Trail is one of the prettiest trails in the state and because of this it is also extremely heavily used. Do not plan on camping at Green Lakes at all. If you must stop for lunch there is an open, grass covered hillside on the north end of the lake trail. Avoid this area except to just pass through if at all possible.
You can ride from Devils Lake to the Fall Creek Trailhead if you don't mind crossing the highway a few times. You can mostly get off to the side of the road enough.
There are toilets and usually a wilderness guard with a radio in case of emergencies (of either kind!) at the Fall Creek Trailhead. There are meadows and lots of feed at the Sparks Lake area across from the trailhead.
Soda Creek is a popular trail with horse folk and several loops can be made using it. The trail between Green Lakes and Crater Creek at the base of Broken Top is very scenic and easily graded. One note: near Cayuse Crater there is a steep drop off which gives some people the willys.
The base of Broken Top at Crater Creek is about as plumb pretty as it gets. There are lots of cross country loops to be had from here but feed is sparce so don't plan on camping here. I like a loop that starts at Crater Ditch Flat and goes all the way around Ball Butte. There are several variations in access that you can take to do this. While it was once pretty decent road, it is now very rough to drive to Crater Ditch Flat from Hwy. 46 even if you have enough clearance and are not pulling to much weight.It is extremely rutted and washed out these days (1998). I do not reccommend it! But you could ride in from the new Todd Creek Horse Camp to reach this area via trail or road. The Windigo-Metolius trail and others rise up from here and nearby Todd Lake. All of the green x-c ski trails make for good riding and are marked with blue diamonds but you may have to skirt deadfall.
From the Ball Butte cross country route it is possible to cross over to Golden Lake. Again this is not a ride for the faint of heart but I have done it or parts of it several times. The tricky part is crossing the crest of Tam McArthur Rim and dropping down to the high meadows below. The route is easier to find going from south to north as you are going downhill. Look for the pass just to the east of the largest chunk of Broken Hand. You will have to cross a snowfield at the top. Get off and walk the steep parts and when crossing snow. You can also drop down into Three Creeks from up here via the Sunshine Road.
The Eastern Section Park Meadow makes an excellent horse camp. It has plenty of feed, shelter, and water. The views are outstanding and several side trips can be taken from this location. One note: this is a popular spot so try to conceal your camp from the view of others so that they may also enjoy a sense of solitude. I suggest that you do not camp at the creek crossing as this is usually used by backpackers. Instead, go up or down the meadow, seeking a secluded spot. Be sure to rotate your grazing often so as not to wear out the meadow. You may find some very secluded spots if you venture downstream from the main meadow into one of the smaller open areas there.
I'd suggest that you park near the road into Three Creeks or at Three Creeks campground instead of trying to drive all the way into the actual trailhead as the road is very rough in a few spots. But others do it all the time so it is up to you. The ride in is so easy that you may as well get the most out of it. There are trails into the meadow from Three Creeks Camp proper (#4075) as well as a short distance before the campground (#99). You will see the sign pointing down the access road and some obvious parking spots.
For a spectacular view of the Three Sisters take trail 4070 nearly to the summit between Park Meadows and Green lakes, looking for a side trail that turns southeast. It is not marked. Follow it into the scenic basin of Golden Lake. Go around the lake at the southern end and look for the stream that feeds it from the hills above. Follow the primitive trail that goes up next to the stream. You'll pass two very pretty alpine lakes eventually topping out at timberline. Continue east until you arrive at a large green meadow. Deer and wildflowers are abundant here in August. You can proceed further east until you hit the wall of Tam Mcarthur Rim. If you know how, you can climb out of the basin (see above) but this spot is easier to drop into from the rim as you can make out a line of travel easier. In all, this high plateau just below the summit of Broken Top is one of the most scenic spots in the state. I love to camp at the high meadows here and am usually alone.
You can make a loop out of this route by following the climber's trail down that follows the draw of the East Fork of Park Creek, though the trail is steeper than the Golden Lake route. You will come out at Park Meadow's south end. Be advised though that the last time we tried the climber's trail it was so faint that I lost it in several areas and we got into some very nasty spots. The climber's route is most obvious climbing up from down below so try it going uphill first so you know the route.
Another great side trip is to turn north instead of south at the Golden Lake trail intersection. Look for a faint track that has been filled in with rocks for the first little way. This is an old, abandoned trail that travels to Red Meadow. On your way to Red Meadow, head west just before the trail starts to drop into Red Meadow. The drop into the meadows is obvious as you descend rapidly. Stop and go back a ways to before where you just started to drop. There is no trail. Just semi open pumice fields that head westerly. Eventually you may find a rock cairn or two along the route. Do not drop into the first draw that you see. Keep above it until the creek rises to meet you more or less. Cross it there and continue in a northwesterly direction until you eventually come to a cliff face that soars several hundred feet above a feeder creek to Squaw Creek. Hang your feet over the edge and savor another spectacular view of Middle and North Sister and Demaris Lake. The trail actually continues on down the cliff but the route has been washed away in places and extremely steep. It is dangerous even for foot traffic.
Red Meadow is very lush but quite boggy. You may be able to find a place to camp there but we have not tried.
Stock up on water while travelling the east side of the mountains from here to Yapoah Lake as it is very hot and dry. The only water is at creek crossings except for one small lake near Red Meadows. Climber's trails ascend Soap and Alder Creek and may provide some additional riding but I have never tried either.
The side trail to Chambers Lakes is worth the trip as it takes you into the heart of the mountains. Past Camp Lake it is very rough however (see above).
Pole Creek is a popular entry point to the east side wilderness.
That is pretty much it. Keep your impact to an absolute minimum. Kick apart your manure, rotate your grazing spots, hobble stock that paws, keep out of the lakes, use high lines with tree saver straps and the whole bit. Make sure that stock users will still be welcome when you leave. Clear some trail, repair some water bars, and break up old, unneeded fire rings.
Chuck Engel