A Tatoosh multi-peak traverse is a way to enjoy fine scenery and bag a few peaks while enjoying relative solitude, especially compared to the herd hiking up to Camp Muir on Rainier. It can be done as a spring ski-traverse if you have AT or tele boots you can climb in, but beware of avalanche danger and breaking cornices here. It's an un-crowded climbing experience, mostly traversing ridges, but with enough alpine rock climbing thrown in to keep casual hikers away. The agreed-upon summits of the whole traverse are: Stevens, Unicorn, The Castle, Pinnacle, Plummer, Denman, Lane, Wahpenayo, Chutla, and Eagle Peak. There are others in the range, too, but these are most objectives for climbers/skiers.
Smaller-combination traverses are recommended until a climber knows the area well. To do a popular full-day traverse on the east end of the Range, start at the Snow Lakes trailhead. Earlier in the season (March to 1st of May) you'll probably have to ski down the road east of Reflection Lakes to access this trailhead, as the road is not plowed beyond here. Ascend to Snow Lakes, passing on the west side, then ascend a steep gully southwest of the lakes to access the snow couloir for Unicorn (another small, unnamed peak lies to your right on the approach, forming the col). Crossing it and turning left takes you to the south face of the peak. You'll find an access gully up this face, and top out on a plateau, but you're not finished. Unicorn's 'horn' is directly north of you. Drop along the right (east) side of the summit ridge for a hundred yards or so until you gain a chimney that looks like it will go. Expect 4th, low-5th class climbing. To descend, re-trace your route.
After Unicorn, you have a long traverse on a sweeping ridge to hike, taking you toward The Castle and Pinnacle Peak. They are located directly on this ridge, and the route along the ridge is easy to pick out, as it is virtually all alpine.
Castle is the blocky one you reach first. Try ascending the south face of it (low 5th, but treacherous when wet). You may wish to use some protection here, as a fall would be nasty. If the chimneys here look daunting, try moving left around the west shoulder of the peak, where you drop a bit, then traverse out onto the north face and a series of steps that will lead you to the summit. Descend the south face (or re-trace the west-shoulder, north face traverse) and drop down the south face of Castle Peak* to find a break in the ridge that will lead you to the west and Pinnacle Peak. Finding the right chimney can be a little time-consuming, but keep looking - and there is more than one option. The first chimney is about 200 feet down (in elevation) from the summit pinnacle of Castle; there is another further down, and probably others I haven't discovered.
(*If you've had enough fun for one day at this point, or want to just bag Castle and Pinnacle that day, the east side of The Castle contains the escape / 2-peak only route. From Reflection Lakes (parking), if you just want the Castle/Pinnacle traverse, you can ascend this route, then descend from the Pinnacle-Castle couloir described later, or, reverse it by doing the P-C couloir first, ascend the chimney in the south-trending ridge, bag Castle, then descend on the east side - then turning north toward Reflection Lakes).
Once you've reached the broad snowfield (or talus, if later in the season), you can see a ridge on the skyline tending south from the summit of Pinnacle. That is your target. The traverse is pretty short (compared to the one you did from Unicorn), and you'll pass a couloir on the left (top of the ridge between Pinnacle and Castle) that is the easiest return to the access road. If you need to bail, here's your chance. But oh... not YOU! Keep going across the south face of Pinnacle, to a prominent tree on the ridge. Turn toward the summit here, aiming for a gully that is poor to protect, but pretty solid 4th-low 5th class. If it is covered in snow, test the depth, as it melts out from beneath and creates a nasty hole to fall into. The gully is a full rock-pitch, topping out on a platform where you'll drop the rope and turn right to wind around rocks and small trees to the summit.
And what a view! Descend to the P-C couloir, then point north toward your car.
Coming in from the west, you might want to tackle the west-side Tatoosh peaks. Chutla is easily combined with Eagle just to the north on the same trip, and sometime is climbed in combination with Wahpenyao. The driving approach is different than the east side peaks: From the Nisqually (southwest) entrance to Mt. Rainier National Park, follow the road ~7mi to Longmire. Turn right at the entrance near the Longmire Wilderness Information Center and park. Walk through the housing area for the park employees, crossing a narrow one-lane suspension bridge over the Nisqually River. The trail starts on the left/east side of the road, a short distance past the bridge.
The trail past the bridge takes you directly to a basin containing Eagle and Chutla; Wahpenayo is a bit hidden from the basin until you get higher on either of the two other peaks. Start with angling toward Eagle on the north, traversing to a saddle between it and Chutla, then scramble down the south ridge of Chutla to access Wahpenayo. After climbing the third peak, retrace your steps to the west, and drop down into the basin (you'll be on the south side of it) to return to the trail back.You can also access Eagle from the north along the Longmire Road, and complete the traverse bagging Chutla then Wahpenayo, but you will not be returning to your car easily this way - unless you desire to bag the first two a second time that day. And, you'll be looking for an access trial you haven't hiked earlier that day, through deep forest.
If you want a climbing experience in Mt. Rainier National Park, and haven' the time (or patience!) for climbing the 'big bro', consider the Tatoosh Range - the only dilemma is... how many to do?
Take Interstate 5 to exit 68. Turn east onto US highway 12 and continue for about 30 miles to Morton and State Highway 7. Take 7 north to a T-intersection after crossing the Nisqually River in the small town of Elbe. Turn right and follow this road through Ashford to Rainier National Park. There are signs for the National Park along the way.
To reach the West entrance by Longmire, take Highway 7 from Tacoma 35 miles south to Elbe. Follow the signs to Mt. Rainier National Park and drive east about 15 miles to the park entrance.
For the east side peaks, follow the main road to Longmire and continue East past the turn off to Paradise and onto Steven's Canyon Road. Routes begin at Reflection Lakes (where the road may be blocked by snow in early season), or2 miles east at the Snow Lake Trailhead on Steven's Canyon Road.
A National Parks pass or daily permit purchased at the entrance station. If you arrive before the station is open, they may hit you for it on the way out. A backcountry permit is required if you choose to camp at Snow Lakes or along the traverse.