A trip up Mailbox Peak via the Old Trail (7.3 miles roundtrip) – another hike checked off the bucket list. The views from Mailbox are phenomenal, but you will pay for them. Ascending via the Old Trail is essentially a 2.6-mile scramble over an exposed root system with 4000 feet elevation gain; certainly a tough hike that is extremely steep, challenging and perfect if you are looking for a killer burn or training to summit taller mountains, like Mt. Rainier or Mt. Baker. We loved it, and plan on doing the hike many more times!
We arrived at the parking lot around 8am, planning to beat the crowds; however, the trailhead was starting to get busy. There are two parking lots that can be confusing, but both will get you to the trailhead. The trailheads (New Trail and Old Trail) are located through the gated road. If you’re planning to do the Old Trail, you’ll continue past the trailhead for the New Trail up the road for a few minutes, then you’ll see the trailhead for the Old Trail on the left with warning signs and advisories from Search & Rescue and the King County Sheriff. Take a minute to read them.
The trail starts off in the sheltering forest with tiny switchbacks (basically straight up) and continues like this for about two thirds of the way. There’s a tree blown down that you have to duck under near the beginning of the trail and one or two more that are easy to climb over. Otherwise, the main condition of the Old Trail is just straight up with lots of roots to climb over. It’s very easy to feel like you’re lost, since there isn’t a defined trail anywhere. Look for the white diamond reflectors on the trees; they will keep you on track. 
There’s a blue “sign” on a tree to look forward to at 1000’ vertical feet from the creek. It took us about 30 minutes to get to this point from the trailhead.
The tiny switchbacks eventually fade out, and the trail is immediately taken over with a moderate-to-severe grade incline of tree roots. There is no defined trail, just lots of stepping over roots. Use the roots to your advantage, as they give you something to grab onto as you’re climbing up!
You’ll then start exiting the forest and merging with the New Trail. There’s even a small portion of intersection. Turn left and prepare for a tough final push to the top. This is a great time to hydrate and eat something. The last half-mile is pretty much a scramble, as the trail steeply climbs the ridge over a tangle of roots and rocks. Not far from the junction, you’ll emerge from the trees to see the 
exposed summit in the distance. Press upward and follow the train of people over rock and loose soil to the mailbox. The views are unbelievable!
The 4822 ft summit is amazing. There is a brand new mailbox that is already stuffed full of random ‘treasures.’ Make sure to sign your name in the log book. We could see Mount Si, Teneriffe, Defiance, Bandera and even Iron Horse Trail. You’ll get breathtaking views of the valley and all the way to the city. Rainier is right in your face. Take a few minutes to sit down for a well-deserved rest and fuel break. We reached the summit at just over 2 hours.
To save our knees, we headed down the New Trail (4.7 miles), which is a very well built and well-graded trail. It was also deceiving, not having any idea how far we’d gone, because we didn’t come up this way. Down was a bit faster than up, and we made it back to the parking lot in a little over an hour and a half. Overall, this was a fantastic training hike and we plan on repeating the adventure many times!
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