My friend and I hiked this series of trails as a 3-day backpacking loop starting and ending at Deer Park.
We opted to go counterclockwise, as it seemed less physically demanding (it meant we didn't have to go up from Cameron Creek to Grand Pass, which was steeeeep) and I think it gives nicer views, since you get to look into the Olympics during the Grand Ridge traverse.
Day 1 was about eleven miles from Deer Park to our campsite at Moose Lake. Maiden Peak was under some clouds, but otherwise the rest of the route was clear with incredible views in all directions. Trail was in great condition the entire way, just a lot of walking on a side slope and a lot of sun exposure. Once we made it to Obstruction Point, we opted to stay high on Lillian Ridge rather than take the Badger Valley cutoff which I think was very worth it! The descent toward the lakes from this route is harder on the knees but the views are so nice.
I'm quite happy we ended up staying at Moose Lake because despite the gnarly toilet (I'd avoid at all costs) there were virtually NO mosquitos. It was incredible. We chatted with many fellow backpackers who had camped at Gladys and it sounded like a rough time. In place of mosquitos, we did have rather aggressive deer who were not shy to approach us and our stuff. I woke up several times in the middle of the night to hear them licking my (empty) backpack
Day 2 was pretty short, only seven miles to reach our campsite at Upper Cameron. We also added in a super short side trip up to Grand View Peak, which is only 1/4 mile off trail and an extra 300 feet of gain to get 360-degree views. Absolutely worth it. From there, it's a massive descent into the Cameron River Valley, which felt a bit demoralizing since we knew we would make up for all that loss later in the day by going back up to our camp at Upper Cameron.
This section of trail along Cameron Creek between the Grand Pass junction and Upper Cameron was the worst we encountered, maintenance-wise, on our route. It was never that bad, but certainly overgrown and had some trees across the way. We ran into a very friendly ranger who had de-limbed some of the fallen trees earlier in the day, which made them much easier to hop over (thank you!) Cameron Basin is beautiful and it was surprisingly empty for a Friday night -- only two other groups. Mosquitos were significantly worse up here.
Day 3 was our longest day around fourteen miles. We backtracked two miles along the Cameron Creek trail and then continued onward and downward on Cameron Creek until we reached the Three Forks junction. This section of trail was overall uneventful -- a classic river ramble -- but, the berries were popping off! I nibbled on some of the best salmonberries I've had in a long time, and even some huckleberries were ripe. We ended the day by heading up Three Forks, which is entirely uphill, but is so well-graded that I hardly noticed. It's mostly shaded and was pretty breezy. The only thing to note here is that there is no water whatsoever once you leave the Cameron Creek junction, so do stock up before you make the ascent.
After that it was back to the car and a rough summer Saturday wait for the ferry back to Seattle!