I was unable to find a Green Trails map Mt Tebo #199, but the USFS has a decent pdf of the area. 

Driving directions were correct but I would say that it is closer to a quarter mile from the four-way junction to the trailhead. We drove farther and ended up at the Lebar Horse Camp. No bathroom there, but more parking if the trailhead is full (and the horse trail intersects with the "regular" trail, so you don't have to walk back on the gravel road to start hiking). 

There was one large, downed tree that our party was able to climb over and one limb across the trail that we hiked around but otherwise the trail was easy to navigate. All stream crossings had rocks to hop across if not actual bridges. 

We encountered very few bugs (just a handful of bites among our group of 6) and no other critters besides a few garter snakes. The dogs we encountered were well behaved. 

The hike is as described - a wonderful walk through old growth with a few peek-a-boo glimpses of the South Fork Skokomish. There is up and down and switchbacks but with all of the flat and many nice places to rest, it certainly didn't seem difficult.

We hiked around 4.5 miles from the Lebar Horse Camp (so your milage may vary slightly from the trailhead) to a wonderful spot to camp by the river.

At around the 2.5 mile mark, we saw a beautiful campsite on the left side of the trail. Here you can walk over the berm and down to the river, where there are more campsites. After this point, we went over two bridges with handrails and then come to a series of switchbacks down. After crossing two more bridges with handrails, we were at around 4.5 miles. At the far end of the 4th bridge, we started bushwacking down along the stream. We could barely see a "trail" but kept making our way towards the water. Once we got out of the brush, we headed right and found many lovely campsites on the sand. There were logs to sit on and trees for shade. We were able to splash around in the river and enjoy the area all to ourselves. 

Scheduled Mountaineers Oly Branch hike. Started from LSF Skok trailhead. Trail unobstructed and in good condition except for one 32" dia. tree on ground across trail about 3.3 miles from trailhead.  We encountered a WTA trails party just east of "Y" intersection with side trail to FR-2394, and thanked them.  Per Caltopo, gained 1,305' to that point.  Almost no mud, nor bugs.

My partner and I took our two 8-year-old daughters backpacking this weekend.  It was the first trip for my partner and his daughter. I found information about overnight camping options on this trail inconsistent between multiple sites, so I wanted to leave this report. The 800 ft elevation gain is right in the beginning --a big up, then a steep descent.  At approx 2.5miles, we stopped at a campsite along the trail and then followed a small trail from the site down to the river.  There were a few spots along the river to camp - some more exposed than others.  We found a great shady spot for our camp with a lovely little riverside beach. The river was calm through this area and the girls were able to play safely.   The following day, we hiked the rest of the trail but there wasn't a destination to speak of. We happily spent the rest of the afternoon playing by the river.  I'm so glad we stopped there rather than trying to get to camps I read about around mile 4-5.   All-in-all it was a great beginners backpacking trip for our girls.  

 Heads up about a ground nest.

WTA has had work parties out on the 140 Access Rd/Homestead section of this trail 24, 25 & 27 Jun working on clearing brush from the stock corridor (8' wide x 10' high), improving the tread (widening and reducing the out slope/"tilt" of the tread), and realigning a section where a 4' diameter log had fell across the trail corridor, leaving only 7' above the trail, and the off trail end more than 10' above the ground.

  We made significant progress in brushing and tread improvements,  and finished the realignment.   There is still a lot of work remaining, but all 3 volunteer crews did a great job on what was done.

  On the 27th one of the tread improvement crews disturbed a GROUND NEST of either bees or hornets (the crew didn't hang around to figure out which one.)  In the attached picture, which is just over a half mile from the trailhead,  look for the section of tread not worked (its still grassy as compared to the wider tread before and after that spot).  You can see the big log over the trail just below.  

  At the end of the day we were able to quickly walk by the spot and only a couple of us were "closely inspected/buzzed".

We left late so arrived at lunch time on a Saturday and there were several parking spots available. We parked at the trailhead but first walked back towards the bridge there and took the footpath on the right (just before we would have crossed the bridge) and were able to have a river side picnic before heading out. Then we took a very short day hike just a couple of miles in to get to the river. Only passed a couple of hikers going in the opposite direction, had the side of the river all to ourselves, and saw nobody on our way back. We've hiked this trail many, many times over the years (lots when our kids were small) and it's usually busier at least on the trail, altho we've always been able to get a parking spot. A great day - last minute plans after getting the WTA email informing us it Washington Trails Day!