There is what is known as the Eastern Loop Trail in MRNP, utilizing the Wonderland Trail over Panhandle Gap, the Owyhigh Lakes Trail and the Eastside Trail. This loop takes one through high alpine and lowland old growth, a gem for sure. A complete description can be found here.
With this in mind, one can complete a loop further east, forging out to the PCT and heading north. The PCT pops in and out of the park boundary along the way, but the majority of this hike is within the confines of Mt. Rainier National Park. This East Eastern Loop has stats similar to the Eastern Loop, with 31 miles and 6,600 feet of elevation gain/loss. I completed this loop on July 28th, experiencing heat, bugs, hail and rain, then sun again. IOW, all the makings of a great trip (I parked at the Stevens Canyon entrance). However, in retrospect I would say this loop is probably best done in the fall, before the early snows hit the upper reaches of the PCT. It suits itself perfectly with its wonderful old growth forest trails, with open views along the PCT above 5500 feet. A fall hike with crisp air, no bugs and late season colors seems especially inviting. This is not to say my summer jaunt was without its rewards. Anytime one is out in the mountains one can expect hindrances to outdoors bliss. In my case it was rather warm (for Washington) temperatures and an abundance of skeeters. However, the wild flowers were a bloomin' and the oppressive heat was mitigated by cool breezes. In my case, approaching 20 miles on my feet, the low point was feeling ill as I climbed out of Dewey Lake towards the high point near 5900 feet above Chinook Pass. The heat was taking its toll. Relief came in the form of sudden hail and rain. While the tourists in T-shirts were scattering (this point is close to the parking area at Chinook Pass), I reveled in the cooler temperatures and made a quick recovery. As soon as I turned on the Eastside trail and headed south, I spent the last 11 miles of the loop in solitude.
Although this loop offers plenty of camping choices, most on the PCT portion and Deer Creek camp on the Eastside trail, the terrain is mild enough to make a most excellent day trip if one has the legs. The Laughingwater Creek trail offers a prime example of old growth forest hiking, gaining altitude on a gentle grade, slowly transitioning to the more alpine environment above 5000 feet. The PCT portion offers views towards the mountain and rolling trail interspersed with lakes, bogs or tarns. And although I found the northern portions of the Eastside trail in sometimes poor shape (blowdowns, rutted sections), the southern portion finds one back in old growth forest with splashing creeks, eventually crossing the Ohanapecosh River and listening to its gentle roaring all the way to your waiting vehicle.
DESCRIPTION: From Stevens Canyon entrance (park at the Grove of the Patriarchs area) proceed across the road to the Silver Falls trail towards Ohanapecosh. Take the Laughingwater Creek trail, crossing Highway 123, to intersect the PCT northbound. Once above Dewey Lake, go left on the Naches Loop trail (still signed as the PCT) until reaching Chinook Pass, then go left on the Eastside trail, which will take you back to your waiting vehicle.