2 hikes starting from the same trail head: Upper Dungeness River trail #833.2. 
Traditionally Marmot Pass is reached from east #833.1. This approach from the north, camping at the fork (2-3 sites right by the roaring river), allows exploring two river valleys with quite different scenery.Day 1. Caught the 8:45am Seattle - Bainbridge ferry. Arrived at the trail head (2500 ft) ~11:30am, had lunch by the river,
pitched the tent @ mile 1 (2900 ft) at the fork by the bridge. Crossed the bridge to the left for Marmott Pass ~1pm. Mossy floor, flat and soft, not too much undergrowth. Rhododendrons. A few small creek crossing. Almost always at the river edge. Very pleasant. @mile 3.4, a side trail to the right leads down to Camp Handy (3100 ft) on a sizable meadow by the river. Looks nice, already a tent.Uneventful, trail starts to gain elevation. @mile 6.4 (4950 ft, 3pm) reached the junction to Home Lake Trail #893 (follow it for a minute is the Boulder Shelter, very nice camping site). Turn sharp left and up. Zigzag. Trees soon disappear.
Flowers filled the slopes. Very colorful, some I have never seen before: Cinquefoil, Cascade Wallflower, Lance-leaf Stonecrop, Catchfly, Crazyweed, (white) Yellow Willowherb, Cliff Dwarf Primrose, Sickletop Lousewor, Moving Polemonium, Hookedspur Violet, Water Speedwell, ... Photos! Dry. Hot. Finally, almost at the end, 2 snow patches to refill the dwindling water supply. 
Reached Marmot Pass @mile 8.1 (6100 ft) shortly after 4pm. Here, you can see Puget Sound (3 cruise ships!) and the Cascades in the distance. A small group camped in the large flat meadow just east of the pass, quite a few climbed the brown Buckhorn Mountain to the north. Windy, much cooler.
A knob immediately to the south (right) is not to be missed. Steep, slippery (I fell), little flowers dancing in the wind. A lovely flat meadow on the top, perfect for camping (albeit with company). 360° breathtaking view. Turned back ~5pm. By then, Camp Handy is crowed. Back to the tent ~8pm (1 mile from the trail head). Chilly. Total for the day: ~16 miles.Day 2. A late start @10am. Hot. Royal Creek trail #832.
Same mossy floor with rhodies (mushroom in autumn?), but no longer so close to the water. Mostly shaded, but drier and warmer. A couple of camp sites. Ran into an owl @11:30am. Didn't even see him, until his wing flapped my hat. After noon, trees thinned out, yet mosquitoes appeared. Occasional views promise fine vista ahead. @~5.3 miles (4700 ft) enter the Royal Basin: a large willow flat crisscrossed with small creeks and super boardwalks or steps. Mosquitoes. Large camping area (quota limited). A short climb to Royal Lake (~5100 ft, @~6.1 mile), green, nice setting, water not too cold. Air is still hot. Mosquitoes. 7 separated camp sites + 1 group site. The lake is supposed to be ringed with thousands of shooting starts. I saw less than a dozen. Not sure whether I was too late (many flowers are in seeds) or too early (still a few avalanche lilies).
Followed the trail to the right (west) of the lake. Soon a fork to the right going down to the ranger station set in the middle of an idyllic meadow, eventually leads to a wonderful cascading waterfall. White bog orchids thrive in its mist. Retraced back towards the lake. 
At the fork, head towards a giant boulder, the trail continues up the Royal Creek to the gorgeous upper basin. Lushly green. Finally saw the long awaited snow patches. The view gets better and better. Further up among heathers and rocks is another rocky basin with a sky blue lake (~5700 ft), snowy faces of Mt Deception to the south, Mt Clark & Mt Johnson to the west, almost at arm's reach. Saw one tent, 3 more hikers and a baby.
Turned back down ~4:15pm (lost 45 minutes looking for the camera). Arrived at the tent in 3 hours. Back at car @8. 1 hour wait at the Kingston ferry. Arrived home shortly after midnight. Total: ~15 miles (+ 1.5 for the camera).
Practicality: US 101. turn left onto Louella Road (just before reaching the Sequim Bay State Park entrance). In 0.8 mile turn left on Palo Alto Road (if you missed the previous turn, Palo Alto intersects 101), for 5.7 miles. Follow the sign: turn right to FR 2880: gravel. Descends to the Dungeness Forks Campground in 0.9 mile. In another 0.8 mile bear left left on FR 2870. In ~9 miles reaches the bridge to the Upper Dungeness trailhead (also a camping ground). ~2 hrs from Kingston ferry or 2:15 from Bainbridge ferry.
