Flatirons Bushwacking/Walker Ranch/Eldorado Canyon marathon

Trip date: March 17, 2018

Caltopo map here: caltopo.com/m/DEV3

I'm starting to get serious about training for my attempt of the Pffifner Traverse this summer. This ~80 mile backpacking high-route follows the continental divide from Milner Pass in RMNP to Berthoud Pass. Depending on the exact route and itenerary you take, it features about 40% off-trail travel and between 4000-5500 feet of elevation gain per day.

I wanted a long hike with a good mix of off-trail travel and large elevation gain. There was snow/rain in the forecast for higher elevations so I was stuck in Boulder. The Walker Ranch loop has nice views, but only moderate elevation gain and is relatively unexciting. The Boulder Skyline Traverse is much more intense with over 5400 feet of elevation gain over ~16 miles but is nearly as boring with 100% on trail travel.

What I opted for was my own hybrid. I'd start at the South Mesa Trailhead (near Eldorado Canyon) and follow the trail west until it hit the base of the Flatirons. From there I'd skirt along the north edge of The Matron, bushwhack up and over the long south ridge of South Boulder Peak, follow the Eldorado Canyon Trail to the Walker Ranch Loop, and then head back east towards Boulder exiting through Eldorado Canyon State Park. Compared to the corny Boulder Skyline Traverse promoted by REI, this route is longer, more difficult (since roughly half of the elevation gain is off-trail), has better and more frequent water re-supply options, and travels across more interesting terrain. (Of course, you'll have to treat all the water you collect except at the visitor center in Eldorado Canyon State Park).

The southern edge of the Matron. It transitioned to light scrambling higher up and eventually crossed a stable talus field.

Looking north from the top of the northern ridge of South Boulder Peak.

One of the reasons I suspect this particular route will have few takers: It's not easy to tell in this picture but this was a nearly vertical descent covered in pine needles. Fortunately this was fairly brief.

Stable talus field on the descent on the western side.

Looking back east towards the ridge I crossed. The talus field in the preceding picture is the gray area between the trees.

Looking east through the throat of Eldorado Canyon. If you squint you can see tall buildings in downtown Denver.

Looking west through the main canyon in the middle of the Walker Ranch Loop.

Another part of the same canyon.

I'd remembered admiring this tree from the first time I did the Walker Ranch Loop. It was nice to see it again.

Looking east towards Eldorado Mt.

These views of Indian Peaks Wilderness never get old. Looking forward to traversing them in one big go this summer.

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Postscript: 
During writing this I've realized that the area around the Matron is actually closed for nesting raptors until July 31 (my bad...).  I've come up with a slightly longer and more intense alternative that avoids this area (see the Caltopo map).  Instead of crossing over to the west side by The Matron it follows the trail up to South Boulder Peak (like the Boulder Skyline Traverse) but then leaves the trail and descends the western side until it connects with the trail leading to Walker Ranch.  It also avoids the ~ 2 mile road walk from Eldorado Canyon back to the South Mesa Trailhead by instead following the trails that lead out of the Doudy Draw TH.  

I'll be back in a week or two to test this alternate route.  From looking at the satellite imagery I'd be incredibly surprised if the off-trail portion isn't easier than the original route.