OverviewRainbow Peak is a spectacular viewpoint above Turnagain Arm fjord just south of Anchorage. The local wind and sun patterns make it, very often, the first Chugach peak to open to essentially snow-free hiking in the spring and the last to go into winter conditions in the fall. It offers a great conditioning hike with a 3500-foot gain or a worthy goal in its own right. The gentle meadows on the southeast shoulder, halfway up, make one of the nicest picnic spots you will ever find. It's a good place to view the bore tide.
Take the Seward Highway (Alaska Highway 1) south of Anchorage, traveling about six miles beyond Potter Marsh on the southern edge of the city. There is a large, paved parking lot about seven tenths of a mile south of Milepost 109. This unmarked parking area serves the Rainbow trailhead.
Southeast Ridge Trail:From the southwest corner of the parking lot, follow the Turnagain Arm Trail across a field and into the woods along gorgeous Rainbow Creek. Follow this well-maintained trail about a mile back toward Anchorage, crossing a dirt road and continuing up a few switchbacks. Where the trail crests at 900 feet, you'll see a viewpoint to your left and a rubble-filled trail heading up to your right. Keep walking about 40 paces till you see a smaller trail heading up to the right. Take this. If you start a significant descent, you've gone to far.
The little trail takes you up some very steep terrain with unpleasant footing for the first 200 vertical feet, but it does get better. About 1100 feet of climbing on short switchbacks brings you onto the magnificent southeast shoulder, with wide-open views of Turnagain Arm and the Kenai Peninsula. After a few minutes of gentle trail walking across the shoulder, you resume the steep ascent with 850 feet of class 2 scrambling up the rocky crest of the southeast ridge. (Stay on the crest here--quite a few people seem to veer into the gully to the right, and they regret it).
At the top of this rocky section, you'll encounter a distinct subsidiary summit, Point 2900. From here, a trail heads off to the right, running level along the 2900-foot contour. Walk this for five or ten minutes till open scree slopes lead to the north ridge. Once on the ridge, walk back to the south along the ridge crest to the summit. Total distance to the top is 2.5 miles, with an average grade of about 28%. Clicking on the small picture at left shows the route traced onto a photograph, as seen from the trailhead parking.
Prow Route:From Point 2900 you can make a fun but exposed scramble directly up the prow above (the upper southeast ridge). The rock is surprisingly solid by Chugach standards. Several variations are possible. The easiest weaves left at first, regains the crest where it is a grassy nirvana, then skirts the biggest gendarmes on the right before returning to the crest in a prominent gully. From there the final big step has several equally delightful scrambling lines. The overall route is Class 3+.
Other routes:NE Ridge: A long class 2 ridge traverse from South Suicide Peak is possible. Allow several hours.
N Face: Trying to link to the McHugh Lake trail via the north flank of Rainbow is not recommended due to heavy brush.
Red TapeRainbow Peak is within Chugach State Park. There are not currently any significant restrictions, and there is no parking fee at the trailhead. My guess is that a $5 parking fee station will be added at this trailhead shortly.
There are beautiful but waterless places to camp on the southeast shoulder. Campfires are not permitted.
Rainbow Peak is a good place to see Dall Sheep, which congregate in fairly large groups on its upper southern slopes in spring, summer, and fall. Bald eagles like to cruise the air currents above these slopes. The woods near the trailhead, having the mildest microclimate in the area and the best greenery in early season, attract a lot of moose at times, and sometimes the moose are not in a good mood. From the southeast shoulder there is a good view of meadows to the east that seem to be popular with bears--bring binoculars to spot them. And the largest lynx I have ever seen was busily marking territory on the southeast shoulder in 2011.
LinksChugach State Park
Seward Highway Scenic Byway
Seward Highway video
North shore of Turnagain Arm (Rainbow is left-most point)
Bore tide viewing guide