Longmire Museum and the trail of shadows
Longmire could be the first rest stop in your trip arund Mount Rainier. There is a restaurant, Wilderness information center and a souvenir shop at Longmire. The Longmire museum house lot of artifacts from the history of Mount Rainier and also has on display, pictures and stuffed displays of the various animals and birds in the region.
A short walk through the cabins and the work area will take you to a woodden suspension over the Niswqually river. Again, good photo-ops.
There is a short trail (0.75 mile) called the trail of the shadows. This trail goes around a small lake and is in the midst of huge trees which practically shut out the sun. This trail goes near a mineral hot springs discovered in 1883 by james Longmire. A good short-walk.