Memaloose Road is on a roll!


Memaloose Road had a rough winter…

Attention geomorphology nerds! (and if you didn’t have to Google that word just now, consider yourself one!) The aftermath of an impressive micro-geology event that unfolded over the winter is on full display along Memaloose Road, in the Clackamas River canyon.

Less than a mile from the Memaloose Bridge over the Clackamas River, a huge new crater appears in the paved road. I stumbled upon the scene a couple of weeks ago, while traveling up Memaloose Road to document the forest recovery from the 36 Pit Fire.


This is no landslide… it’s a crater!

The human-caused fire (started by target shooters, sadly) burned 5,520 acres of the lower Clackamas River canyon in September 2014, including the newly protected wilderness in the South Fork and Memaloose Creek canyons.

At first, I assumed this to be a landslide triggered by the fire burning away vegetation that normally holds down soil on the steep canyon walls. But upon closer inspection, this was clearly an impact crater, not a slide. A 15-foot wide hole has been punched through six inches of asphalt, leaving a 4-foot deep crater in the road!


A few minor repairs may be in order, here…

At first, I thought a large, falling tree might have somehow torpedoed the road, but looking downslope toward the Clackamas River, the culprit was in plain sight. A van-sized boulder had rolled down the slope and is now lodged against the south bank of the river!


Path of destruction… and the answer to the crater mystery!

The boulder did a thorough job of clearing the slope in its path, but what struck me in looking at it from above was just how ordinary this boulder is in comparison to the thousands of mega-boulders that dot the Clackamas River. In this way, the rolling boulder at Memaloose Road is a nice glimpse into the everyday shaping of the canyon, where countless events like this have carved the landscape we know today.


The big, bulldozing boulder resting in its new, riverfront home. For scale, the freshly skinned logs lying next to the boulder are a 18″ or more in diameter. The nearby moss-covered rocks were in place before the rock fall, and may have helped block the new boulder from rolling further into the river.

So, where did the new boulder come from? A view up the slope from the fresh crater tells the story. A low, 30-foot basalt rim lines the top of the canyon wall, and the path of destruction to the road is plainly marked by a mowed-down understory and several shattered trees (below).

Through sheer gravity and cracks that form in the basalt layer, boulders like the one at Memaloose periodically break loose. This is the ongoing erosion process that has played out for millennia in the Clackamas River canyon, and it’s a great opportunity to see this process playing out in real time.


The path of destruction above the road.

Part of me wishes I could have been here to watch the big boulder blast this path, especially when it reached the road cut, which worked like a ski jump to launch the boulder into the air, landing it on the outside edge of the road and creating the impact crater. Wow, what a spectacle! Well, maybe from a safe distance, anyway..!

The best seats in the house for this event were at the base of the road cut, where a colony of Maidenhair Ferns grow along the road (below). They watched the giant, airborne boulder soar overhead, yet managed to miss its wrath. If only ferns could talk…


The “jump” that launched the huge boulder into space.


A closer view of the path of destruction, including several smaller boulders and trees that were brought down the by the big boulder…and the lucky colony of Maidenhair Ferns.

This view (below) looking downhill and toward the Memaloose Bridge (in the background) gives a sense of the size of the crater, and what the impact must have been like. Fortunately, my car wasn’t parked there at the time (…though it does have the required Forest Service trail permit on the dash…) The big Douglas Fir on the left was narrowly spared by the big boulder, and also survived the 36 Pit Fire to hopefully live for many more years. The boulder could have easily snapped this 4-foot diameter tree, and did crush other large trees in its path.


The crater with the Memaloose Bridge and Clackamas River in the distance

The rolling boulder can also be seen from Highway 224 (below) on the opposite side of the Clackamas River, where the path of destruction and jumbled pile of trees and smaller rocks and boulders gives a hint of what happened here.


The big boulder and its path of destruction from the opposite side of the Clackamas River

On the way out, I noticed a fresh pile of gravel at the south end of the Memaloose Bridge, which suggests that road repairs are imminent. So, if you enjoy forensic geology and seeing Mother Nature at work*, stop by the Memaloose Road sooner than later!

How to get there…

The boulder roll took place just off Highway 224 and makes for a short and interesting side trip if you’re headed for a hike further up the canyon. Memaloose Road is easy to find, too. Follow Highway 224 to Estacada, then continue approximately 9 miles to the Memaloose Bridge, where you will turn right to head across the bridge and up Memaloose Road. This is a 1-lane bridge and road – watch for log trucks! The boulder crater is less than a mile up Memaloose Road.

Oh, and watch your step when checking out the crater… it’s a long slide down to the river!


*Mother Nature does, indeed, bat last… always…


Proposal: South Fork Water Works Trail

Lower falls on the South Fork Clackamas River in 1963

In 1913, the young cities of Oregon City and West Linn suffered a serious outbreak of typhoid from an increasingly polluted Willamette River, their sole source of water at the time. The incident spurred Oregon City’s leaders to appoint a “Pure Mountain Water League” and directed it to locate a safer source of drinking water.

The League settled on the pristine South Fork of the Clackamas River in the Cascade foothills. The City of West Linn signed on with Oregon City, offering to pay for one third of the cost of a new pipeline to bring the South Fork water to the two cities. A South Fork Water Board was created to carry out this ambitious project.

By the fall of 1915, the new water district had managed to lay twenty-six miles of 18” pipe from a site at the confluence of Memaloose Creek and the South Fork Clackamas all the way to Oregon City and West Linn. The new pipeline began to carry municipal water on October 7, 1915.

Main falls on the South Fork Clackamas River in 1963

In 1939 the South Fork Water Board expanded the system with the help of one of Franklin Roosevelt’s New Deal recovery programs, the Works Project Administration. This project extended a 24” pipeline upstream from the Memaloose Creek intake to a point upstream, above the 120-foot main falls on the South Fork. This project involved carving a series of three dramatic tunnels and a cantilevered pipeline through solid basalt cliffs.

The new intake improved water pressure downstream, and this system continued to serve as the water supply for the two cities until a new filtration plant was constructed on the lower Clackamas River, in 1958. Both systems were used until 1985, when the South Fork pipeline was decommissioned. Since then, the network of roads, tunnels, plank walkways, log bridges and old pipeline has slowly been fading into the green rainforest of the South Fork canyon.

The story might have ended there, except for the series of spectacular series of waterfalls along the South Fork and Memaloose Creek. By the late 1990s, some of the region’s more adventurous kayakers had scouted both streams, and in the early 2000s, had documented the first known descent of the South Fork by kayak.

Main falls on the South Fork with hiker in 1923

These intrepid kayakers portaged the big waterfalls on the South Fork by following the abandoned tunnels and log bridges left behind by the South Fork Water Board. In doing so, they brought renewed interest to the area, as word of a high concentration of waterfalls spread to other adventurers.

In total, there are five major waterfalls along the final two miles of the South Fork, and two along the last mile of Memaloose Creek, where it flows into the South Fork. The old water works roads and tunnels reach two of the South Fork waterfalls, including the main 120-foot falls, as well as the main falls on Memaloose Creek. The remaining waterfalls are remote, and not reached by the water works roads.

The tunnels and roads along this system are entirely intact and walkable – as several explorers have now documented. A timber bridge over the South Fork at Memaloose Creek is also intact, and is now used by waterfall explorers to cross the stream. These old roads and tunnels offer a unique opportunity for a new trail system that could build on the existing network, and offer an unparalleled blend of natural spectacle, historical artifacts and lots of insight into the history of the South Fork water works project, itself.

(Click here for a larger map)

What would this trail look like? The accompanying maps (above and below) show the sections that would follow old water works grades in yellow. All of these roads have been recently scouted, and are in good shape, and thus easily converted to trails. The six tunnels along the way (one along Memaloose Creek and five along the South Fork) are also in good shape, and easily walked, although at two are long enough that a headlamp is required.

New trails would also be needed to complete the system, and are shown in red on the accompanying maps. A new trailhead and access trail would located on the east side of the Memaloose Bridge, following the Clackamas River downstream, then turning up the South Fork canyon and joining the converted water works grade at the lower South Fork falls (this section along the Clackamas would also serve as an extension of the Clackamas River Trail, extending east to Fish Creek, and the current trail terminus).

Two trail extensions would carry hikers deeper into the canyons of the South Fork Clackamas and Memaloose Creek, beyond the water works roads. A new Memaloose trail would climb a half-mile to a second falls, upstream from the main Memaloose falls. An extended South Fork trail would continue from the final waterworks tunnel, and travel 1.5 miles upstream along the west bank of the river, passing three remote waterfalls before ending at the existing Hillockburn Trail (shown in green on the maps).

(Click here for a larger map)

Look closely at the maps, and you will also see a proposal to add a trailhead at Big Cliff, along the Clackamas Highway, with a footbridge connecting across the Clackamas River to the new South Fork trail network. The concept here is to provide a family-oriented day-use area on this scenic bend in the river that serves as the long-term gateway to the South Fork canyon. Today, this spot is an eyesore – a huge dirt and gravel expanse that suffers from dumping, shooting and other unlawful behavior. The trailhead and day-use concept would turn this blank expanse into a place for families to explore the river and nearby trails, less than an hour Portland.

Future trailhead and day-use area at Big Cliff?

In deep, rocky canyons like the lower South Fork, building new trails is complex, costly and at odds with modern conservation ethics, where blasting a trail through cliffs is no longer an accepted practice. Thus, the ability to convert the water works roads would bring hikers into a landscape that probably would never be reached with modern trails. In many ways, the canyon is an accidental version of the venerable Eagle Creek Trail, in the Columbia Gorge, where the route is famously carved into the cliffs.

The logistics for this proposal are also fortuitous. The water works area of the lower South Fork canyon was specifically excluded from the 2009 Lewis & Clark wilderness act that set aside the upstream portions of the South Fork canyon as new wilderness. This means that while the upper canyon trail must be built with wilderness restrictions in mind, converting the roads, repairing bridges and preserving the historical artifacts in the lower canyon won’t be encumbered by wilderness restrictions.

This is a project whose time has come – in part, because the word is out about the scenic wonders of this beautiful canyon, but also because the historic features ought to be preserved before they are lost to time and the elements.