Zig Zag Mountain sits at the base of the west side of Mount Hood in the Mt. Hood Wilderness. True to its name, the mountain zigs and zags in an east-west ridge formation. The name came from the journal entry of Joel Palmer who wrote a Journal of Travels in 1845 as he made his way from the Rockies. He described zigging and zagging down the SW side of Hood in the canyons there and many times now this name is used in the area to name places such as the town of Zig Zag, Zig Zag Canyon on Hood, etc.
There are 6 main summits on the ridge with the true summit being a bushwhack off the trail. From west to east there are peaks at 4564 feet (a roundish mound covered in trees), about a half mile east is another peak this one craggy and cliffy at about 4484 feet, a short distance further on the ridge is the old West Zig Zag lookout site atop a cliff, a little over two miles east along the ridge is Point 4877 - a bare peak with rocks and beargrass and great views, further on still is the actual summit just under a mile to the east, and finally East Zig Zag at 4971 feet about a mile and a quarter towards Mt. Hood.
There are established trail to both East and West Zig Zag peaks with a nice connecting trail along the ridge. Most hike up to one or the other and some even do the loop for a great workout. Few it seems take the time to identify the actual highpoint of the mountain and bushwhack a few hundred yards up off the trail to the summit. There is a small beargrass filled summit with a fire ring (so no, you won't get a first ascent either).
Views of Hood are amazing and not too many see the west side of Hood this close unless you are on it. The area is popular and easy to get to from Portland. The lower trailhead to West Zig Zag is only at 1550 feet and open most of the year while the upper trailhead closer to East Zig Zag is at 3350 feet so snow levels determine access here.
I've also recently (August 2010) learned that there may be a scramble route up from the Castle Canyon trail. This would be about 3500 feet of steep hiking and scrambling among cliffs. I've not confirmed this except to talk to locals and find the start of the climbers' path but I plan on doing this as soon as possible and will report back. The information I have is that you hike up the regular Castle Canyon Trail (see Sullivan's red "100 Hikes in Northwest Oregon" book for info, and where the trail traverses left over to the "castles" and a supposedly huge waterfall, look for a climbers path heading straight up. I've done some scrambling of this for a short distance but had my dog with me so could not go too far as it gets third class quick. Supposedly this scrambles up through cliffs to the summit (or the trail to the summit).
June is the best time to see flowers here from Rhodies to beargrass to paintbrush to trilium to many others. You pay the price if you take the upper trail through the swampy area though with the bugs. Swarms of mosquitos can plague the area at that time of year. Whenever you go though, the views of this little gem close to Portland will astound you, plus you'll get a good workout in.
Neat site with cool panoramic shots and a good map.
Northwest Forest Pass at the trailheads for parking.
You also must fill out and carry a Wilderness Permit while hiking.