The Osborne Mountain Trail is a VERY hard hiking, mountain biking, and equestrian trail just…read moreoutside of Mount Rainier National Park, in Packwood.
As the crow flies, it's actually just a couple miles outside of Longmire.
There is a high risk of injury or death awaiting anyone who traverses this trail unprepared. Signs at the trail head warn that this is a "more difficult" trail.
There are no accessible areas of this trail. The whole thing is hard, unpaved, uneven, slippery, and steep.
I would not hike this trail during any kind of active precipitation, because, even the day after precipitation, the trail itself is a waterfall in places. It would not be safe to hike in heavy rain.
That being said, for highly experienced hikers, this is a great option to beat the crowds, and get a whole trail to yourself.
The trail starts at the Forest Service Big Creek Campground in Gifford Pinchot National Forest. To the best of my knowledge, this is the closest campground to the park without technically being in the park.
When the campground is open, parking is available at the trailhead itself, located inside the campground. The rest of the year, parking is just outside the gate, and there is room for a maximum of six cars.
From the trail head, it's five miles (each way) to the summit, or six miles to Cora Lake.
3 miles up the trail, there is a rustic campsite with an established fire pit at the saddle of Osborne and another mountain.
When I hiked this on a Sunday, the parking was full. Of the six groups of people I saw, three made it less than one mile, two made it less than two miles, and the only person to make it as far as the saddle was me.
To go any further, I would have needed spikes or snow shoes, food, more water, and emergency camping supplies.
I was out there all day, from about 9am to 4pm. I was hiking at a pretty relaxed pace (for me), but that's still nearly an hour per mile. (I tacked on a couple of miles hiking down the closed forest road that intersects with the trail at mile 3.)
The first mile and a half of the trail were the hardest. This was a very steep, very slippery climb through an old growth rain forest dripping in moss and lichens up to six feet long.
The ground was carpeted in a blanket of leaves that was a few inches thick. Some extra steep areas of trail had been reinforced with strategically placed concrete blocks, but even with these, the footing was very tricky and difficult.
I didn't fall or get injured, but I did slip several times.
Up at the saddle, the ground was covered in snow, which showed me evidence that I was the first and only human to hike that section of trail that day.
I found several sets of animal prints, including bobcat, rabbit, and some kind of mountain chicken (ptarmigon?) (Note that hunting and shooting are restricted in this area.)
Even though the trail was isolated, it was not quiet. A nearby timber operation caused a substantial amount of noise between miles 2-3.
From the saddle, the views of Mt Rainier and nearby mountains was almost as good as the view from Eagle Peak.
I would probably need to hike this trail in summer or as an overnight fall trip to see the views from Osborne peak.
Again, this is not a trail for inexperienced hikers to try without planning. But, for experienced hikers looking for a less crowded, more challenging route, this is great.