Checking the Mail and Getting Dirty on Mailbox and Dirtybox

12 years ago I went on a first date and we decided to make a double-header day out of Mount Si and Mailbox Peak. That’s about 7,150′ of gain in 13 or so miles and we stumbled down Mailbox in the dark with no lights. That was way before they had a flashlight app. And way before I was a hiker. Somehow the relationship lasted 3 years. I think my knees lasted 3 seconds. I haven’t hiked Mailbox since.

Mailbox is a local celebrity hike of sorts. Everyone knows it and if you haven’t hiked it you’re frequently asked why. It climbs relentlessly skyward gaining 4,000′ in 2.5 brutal rooty miles. Your reward is a great view and a quirky mailbox on top filled with all sorts of offerings to the Mailbox Gods.

Warning: this trail is a beast, don't be dumb
Warning: this trail is a beast, don’t be dumb

Now with tons of miles, lots of fitness, and all sorts of crazy steep hikes under my belt I set out on Sunday to finally check the mail again. And the biggest reason was because I had my sights on another peak right next to it called Dirtybox. Dirtybox is the unofficial name of the tallest peak on the ridgeline spanning both Mailbox and Dirty Harry’s. It’s about 100′ taller than Mailbox and requires some class 2/3 scrambling to reach. Not many people seem to go there so naturally it ended up on my “peak wish list”.

From Dirty Harry’s the scramble over to Dirtybox looks downright scary and exposed. A fall would certainly be fatal. But some online research said it was more easily reachable from Mailbox so I decided if it looked safe enough, I’d make a go for it. The scramble wasn’t likely dog-friendly and my usual partners in crime all had plans so I took advantage of a solo hiking day to have a little alone time with just me and the mountain.

Since Mailbox can be very crowded I started up around 2pm when most people were on their way down. After the initial half mile approach, the trail gets down to business quickly and climbs skyward through old forest. Oh yes, I remember how fun this trail is! There are maybe 2-3 very short sections that offer a short reprieve, meaning they’re simply steep and not ludicrous steep. A hiker ahead of me called down to his obviously upset girlfriend “honey look, it’s almost a normal hill right here!” Ahhh, Mailbox Peak: maker or breaker of relationships.

Towards the top of the woods the trail gets a bit tough to follow and hikers have frequently wandered off here requiring the assistance of search and rescue. At last, the trail pops into the open near a boulder field but alas, it’s still another 500-600′ to reach the top.

Nearing the top of Mailbox and enjoying the views of storm clouds
Nearing the top of Mailbox and storms are a brewin’!

From near the top I could hear rumbles of thunder far in the distance as storms gained strength over the Cascades. When I finally reached the mailbox and crested the summit the storm clouds were impressive.

Mailbox Peak with storm clouds brewing in the distance
Mailbox Peak with storm clouds in the distance. Listening to the thunder was awesome!

I stopped for only a few minutes to take some photos and watch a hang glider swooping over the summit, yelling down to everyone “yippee!” He was obviously having a grand time up there! How fun it looked! He circled the summit at least a dozen times, entertaining everyone taking a rest.

A hang glider making laps over the Mailbox summit. He sure was having a grand time yelling down at everyone
A hang glider making laps over the Mailbox summit. Now THAT looks fun!

I looked across to Dirtybox, the exposed ridge line, and the building storm clouds. To go or not to go? Getting stuck here in a lightning storm would suck. But the storms were holding to the east so I decided to go for it with the caveat that I’d turn around at the first sign lightning was getting closer.

Before starting the scramble over to Dirty Box, the peak directly behind me
Before starting the scramble over to Dirty Box, the peak directly behind me to the left.

The ridgeline scramble to Dirtybox drops down some rocks and then pushes through a lot of scrub brush. There are pretty steep drops on either side of the ridge but staying right on center isn’t dangerous. There’s even a faint booth path in sections. I slowly picked my way over boulders, through brush, and popped out onto the top of some rocks halfway over. I could see people on Mailbox pointing my way, probably wondering “How the hell is that person over there?!” Dirtybox doesn’t get much traffic.

Found this awesome little inscription halfway across the DirtyBox scramble. Mailbox is in the background.
Found this awesome little inscription halfway across the DirtyBox scramble. Mailbox is in the background with hikers on the summit.

Once across the saddle it’s just a matter of continuing a scrubshwack across the ridge. Pants and a long sleeved shirt might have saved me some battle scars. Just as I was making my final push to the summit I heard a loud crack of thunder and realized storms were definitely moving in fast and I had little time to get off this ridge.

This was the last picture I took before summitting DirtyBox. Storms were rolling in fast, I needed to get down in a hurry!
This was the last picture I took before summitting DirtyBox, yikes! Storms were rolling in fast, I needed to get down in a hurry!

I scrambled up fast as I could, tagged the summit, and immediately headed down without taking any time for photos. I tried to make it back down and across to Mailbox as quickly and safely as I could, the thunder getting louder by the second. When I scrambled back up the rock to the summit of Mailbox and popped out on the top people were really confused as to where I came from.

With thunder getting decidedly close I made a run off the summit. Minutes after I descended into the relative safety of the forest I was shocked to see people still heading up. Did they not hear all the thunder? Were they crazy? No way I’d be sitting up there right now!

Just as I hit the relative safety of the lower treed elevations, there was lightning and thunder all around, some pea sized hail, and a brief monsoon. Hiking back down in a thunderstorm made for some fun ambiance and I sure was glad I wasn’t on the ridge up there anymore, whew! The rain actually gave the dusty dry trail some tacky traction and considering I forgot my trekking poles, my knees somehow survived intact this time.

The storm blew over and I returned to the parking lot under blue skies, super stoked to have tagged Dirtybox and not died in a lightning storm. Even after hiking the brutally steep Snoqualmie Mountain, Teneriffe, old Si trail, and Humpback Mountain, I think Mailbox still reins supreme as king of the butt kickers.


Round Trip: 5.7 mi
Elevation Gain: ~4000′
High Point: 4,822′
Hiking Time: 1:45 up, 1:30 down

The scramble over to Dirtybox added only about a mile roundtrip and not much elevation gain or loss. I think it took me maybe 45-60 minutes to get across and back. A bit of a slow go due to scrambling, route-finding, and scrub wrangling.

GPS Tracks

Unfortunately I stopped my watch at the top of Mailbox and forgot to restart it, so I’ll have to go back again for an updated GPS track. But this is the ascent to Mailbox.

Mailbox Peak