Mount Jupiter has gotten a bit of a bad reputation because of the recent logging and the presence of a locked gate down low that makes it an awfully long day hike, but I enjoyed a wonderful short overnighter trip up there, and want to ensure others that it's a very worthwhile trip, especially if you want some great views without any crowds.

After turning off Highway 101 on the Mount Jupiter Road just a bit south of Brinnon, drive up the gravel road (ok for most any vehicle) for about 3 miles before reaching the big orange gate, elevation about 1200 feet. From here it's nearly 10 miles to the top, the first 3 or so are on logging roads. What I recommend is to take a mountain bike. The first 2.5 miles of road, up to the traditional (lower) trailhead, is at a fairly comfortable grade and can be ridden most of the way (for me, 58 y.o.) without having to push up many aggressively steep portions.

At the road switchback 2.5 miles up from the gate, elevation 2050 feet, you can find the traditional trailhead a bit to the west, complete with a battered old signboard. You're in a huge clear cut area here. I opted to continue up the road, pushing the bike as it became steeper, and went another mile or so up to an intersection of four roads in a level area at about 2800 feet. You can reconnect with the trail as it passes just below the roads here. I arrived here near sunset time, 2 hours after starting from the gate, and found a nice flat spot to camp on with a great view overlooking Hood Canal and across to Puget Sound and the Cascades. Yeah, you're in a big logged area, but it's still beautiful.

I set out in the morning, quickly connected to the trail, leaving the bike behind at my camp. The trail continues through the clear cut for only a few more minutes, then enters forest and eventually wilderness area. The trail is in relatively good condition, very few obstacles, and I actually made very good time on the way up until it got a little steeper the last couple of miles. 

The critical thing about this hike, as most people mention, is that it is a long, dry trail, and has quite a few sun-exposed sections. TAKE MORE WATER THAN YOU THINK YOU NEED. Actually, fall is a good time to do this hike. A hot mid-summer day would not be the time to go.

The top is spacious and even has a couple of potential bivy spots. Views are exceptional-- the five Cascade volcanoes can be seen if the air is clean, The Brothers and Mount Constance are nearby, Puget Sound City is laid out below, and many summits in the Olympics and Cascades can be picked out. 

I saw no other people during the entire 20 mile round trip. 

I called the forest service and they said they are no longer opening the road for access to the trailhead. They estimate the distance from the road closure to the trailhead to be about 3 miles each way. So, it will make the trip a 20 mile out and back adventure now. Remember, no water on the trail until you scramble down from the summit to the lake, but that's not easy. 

Thanks for previous info on this, I was hoping to hike later in the week.  I called the Ranger Station at Quilcene and they confirmed that the trail will be closed probably through September (no info on their website though, arggh)

I just wanted to write this report as an FYI to anyone wanting to hike Jupiter this season. We went to hike Jupiter today and the gate was open. However there is a sign above the gate that says the Jupiter Trail is closed due to lumbering activity. We ignored the sign, and found the trail head using the great directions from one of the previous reports, thank you! However, not even a mile up the trail, directly uphill from the trail head, trees were actively being cut down. We perceived that the trail probably went directly through the area they were cutting trees, and so decided not to hike. They probably put that sign up because they are planning on cutting all the trees in that area down these season. We also heard lumbering activity farther up the mountain as well, so we are not sure if there is more lumbering activity further up the trail. Just wanted to let you know ahead of time so that you do not go all that way to discover the same thing we did!

I ran solo to the summit; As noted in other trip reports, the gate is closed, and has been closed since I last went out in Oct ‘17, due to active timber harvest.

2.4 miles from the gate, you’ll come to a junction, continue straight for .10, and not to the right, the road is becoming grassy and over grown; and there you’ll find the proper trailhead, to the right of the sign. You’ll go about a mile or two up the trail before it disappears into a new logging road, continue up the road by following the pink ribbons, and the new entrance to the main trail will be on the left. I was pretty devastated to the point of tears to see this mass destruction of the trees. I know it’ll all grow back, but that’s a long time away. 

Anyways, there were only about 5-6 ‘major’ trees to amble over en route to the summit. Didn’t see any wildlife or any other hikers. Beautiful clear day, and very warm. It’s super important to make sure you have plenty of water, because there are no water sources on this trail! Off the summit, there are a couple of way trails that I suppose if you were desperate, and was carrying along a water filter, you could refill from the recent snowmelt, and perhaps melt some of the snow currently sitting below the summit. 

Bugs at the summit becoming annoying, and got me up and going again after a brief 15min break, and then I ran back down to the car. It took me just a little under 4hrs with 19 miles total.