Bottom Line:

First-timer on this trail along the Boulder River, passing three large waterfalls, and countless streams flowing over and under (via bridges) the trail. Canyon hiking that starts in second-growth forest, but transitions to old-growth once one enters the Boulder River Wilderness. HUGE trees, ferns, Hoh-like moss, flowers, a boulder-strewn milky green river and lots of streams and little waterfalls. BEAUTIFUL! This time of year, the waterfalls are mostly in the shade all day. The Boulder River is aptly named with some boulders the size of houses; the water is milky green from glacial runoff. I will be back!

Stats:

• Distance: 6-3/4 miles (might be inflated ~1 mile due to GPS signal loss in canyon)
• Duration: 2-3/4 hours
• Road/Parking: NF-2010 off SR 530 is in OK shape - lots of muddy potholes, but none too deep; any car should be able to make it going slowly enough; lots of down trees but cleared, at least sufficiently so to allow cars to pass; the pass toilet is ~3 miles from the trailhead and is marked as such (!); the trailhead has parking for maybe 10 cars, and I did not see any glass indicating a break-in problem; a National Forest parking pass is required; the mountain pic below is from the beginning of NF-2010 - limited mountain views from the trail itself ;)
• Weather: Partly sunny to mostly cloudy; 50s; no wind
• Water: There is plenty of water on the trail, with no need to carry water if you can filter
• Flowers: Among the flowers on this trail - salmon berry, yarrow, skunk cabbage and butter cup
• Trail: The path up to the wilderness boundary is a road-to-trail conversion, with singletrack after that. The wilderness section of trail is in a beautiful old-growth forest. There are two waterfalls about 1-1/2 miles in located within 50 feet of one another; you may have been tempted to bushwhack down to the river before this point, but there is plenty of trail-provided river access at the falls, where you can get up and personal with "Show" Falls (NOTE: Obstacles like down trees on the small beach); the 1st waterfall is "Pre-Show", and while it is a trickle, it is very elegant and beautiful; the 3rd waterfall is another 1-1/2 miles in, and this is where I turned around; the trail continues a bit, per GAIA; the trail is in fair condition, with a lot of down trees, some mud, spots with washouts and avalanche runout, and flowing creek water on the trail itself; waterproof hiking boots recommended; the mosquitoes were a little annoying but the waterfalls - another season first! Very quiet - only saw two other people on the trail, which was kinda perfect :)
• Takeaway: The Boulder River Wilderness is beautiful - I wish I had taken some pictures of the huge trees! I would like to explore some more - wish there was still access to Tree Fingers from this trail; the waterfalls here are reminiscent of those on the Oregon side of the Columbia Gorge - in a good way! (i.e. minus the crowds, and with a more wilderness feel)

The attached short 4K video will take some time to upload and convert to high definition.

NOTE: It appears one had to log-in to WTA to click a report as "Helpful" now - took me a bit to figure this out!

Excellent hike with our pups! Be prepared for mud and lots of rocks. Trekking poles highly suggested.

The road to the trailhead has numerous potholes, but we made it fine in a low clearance vehicle. 

The old growth forest is spectacular- I even saw some signs of spring (skunk cabbage).

The trail up to the 2nd falls is clear mostly and muddy in places. After the 2nd falls all the way up to the river it's a good hike. Muddy and wet but the views when you get to the clearings are awesome! There were a few larger trees fallen on the trail but they are passable. 

This trail needs some love, just like the road leading to the trailhead. This is my neighborhood hike as it is within 20 miles for me. It never disappoints, no matter the season.

From trailhead to the river is more like 10 miles roundtrip, not 8.6, per my GARMIN GPS.

Beautiful day for a hike on the Boulder River trail. 3.6 mile road from the highway to the trailhead had a lot of potholes, but it was easy to navigate with some care. Trail was a bit muddy and wet, but not bad at all. The waterfalls early in the hike are stunning, and we found a nice sunny spot at the end of the trail (at the river) for lunch. 9 miles round trip, with a bit of up and down. Great early season day hike!

So glad we were able to finally backpack this trail! Arrived at the parking lot around 4PM with plenty of parking and headed in to find a waterlogged trail. Lots of stream crossings (I slipped in one - would recommend poles if you're not sure-footed) and mud but overall wonderful.
Camped at the site on the river, had an incident with mice getting into a snack bag the wad left out while we were setting up camp but otherwise no issues with wildlife. Highly recommend a bear can or hanging your food if you decide to camp out.