The trail was relatively flat, gaining only 500 feet or so in the 10.5 miles we hiked to Lewis Meadow.  After Elk Lake at about 15 miles, the trail vaulted upward to Glacier Meadows on Mt. Olympus, but we didn't go that far.  This turned out to be good, since the Olympus Guard Station at 9.1 miles had a sign posted "Wasps very active along trail near Elk Lake"!