The forecast for Sunday was good (great actually) and I really wanted to get out and do something.  I've wanted to do Hibox for a while now, but kept putting it off as none of my scrambling friends seemed interested when I suggested it in the past.
I got to the Rachel Lake trail head at 8:00am and was one of only 5 cars in the parking lot (and they looked to be overnighters).  By mid afternoon when I returned, the lot was full.  A lot like Kaleetan and the Melakwa Lake trail head.  Pays to get there before the crowds.
From route info I found on-line, I knew that the cut off for the Hibox climbers path was a couple miles from the Rachel Lake trail head on the far side of the second major clearing I would cross.  I'm always a little concerned about finding unmarked side trails, but Hibox is done often enough that I figured (hoped) the path should be pretty obvious.
The Rachel Lake Trail #1313 is a well graded and maintained super highway.  I did find the cutoff (with a little help from a couple of guys headed to Alta), roughly 2.3 miles from the trail head (3300').  It took me a little under an hour to get there and as advertised, it was about 150' inside the trees on the far side of the second major clearing (look for a couple of large sawn logs parallel to the trail and then an old weathered stump). 
The path is level for just a few hundred yards after leaving the Rachel Lake Trail.  If you were wondering when you'd start to gain some of the remaining 3100' to the summit, wonder no more. It wasn't too hard to follow, but it does lack some of the niceties you might normally expect in a trail.  For the most part it stays to the trees on a SW shoulder, climbing to the right around cliff bands, up rocky gully's and stream courses until it emerges onto an open grassy slope still well below the summit. At this point the discernable path disappears, but on a clear day like this, it wasn't hard to figure out where I needed to go (straight up seemed to work). 
Once I reached the summit block, I traversed right along the base of the cliffs until I found the second gully that most recommend, but even that looked pretty hairy to me, so I kept going (NE) to the top of the ridge.  Now this was more like it.  To the left a rocky arete lead up from the SE ridge to the summit.  There wouldn't be much in the way of scrambling after that long slog up to the ridge, but what there was looked like it would be fun.
I went around to the NE side of the arete and scrambled ledges until I had worked my way back to the crest about mid way up. There would be no problem just going straight up the ridge crest from the start, but coming up from the right side looked more interesting to me.  There is some exposure and loose rock.  It seemed worthy of the scramble "T4" rating.  
The summit area is small, really just a jumble of large boulders affording excellent views into the surrounding Alpine Lakes Widerness.  I looked but didn't find a register. In the most likely spot, I found a pencil stub, but that was all.
I spent half an hour on the summit and then headed down, reversing my ascent route.  At about 4800' I took a break on a rock slab with a view out toward Kachess Lake.  Just me and the clicking cicada's in the sun and fine breeze.  A knee bruiser getting back to the Rachel Lake Trail, but very fast from there to the cars.