Tourists will soon be streaming into the Hood River Valley to marvel at the pink and white blossoms that blanket Oregon’s most famous apple and pear orchards each spring, with snowy Mount Hood towering above.
For many, the trip takes them to the tiny farm hamlet of Parkdale, in the heart of the upper valley. Here, the unexpected view of a dark wall of lava known as the Parkdale Lava Flow is a surprise to even longtime Oregonians. This dramatic flow is among the largest and youngest in the Cascades, yet remains surprisingly unknown.
From the farms near Parkdale. the lava flow looks like a ridge of jumbled boulders, with the occasional Douglas fir or ponderosa pine poking out of the chaos. But viewed from above, the formation takes on a more recognizable form. Flowing north from a deep fissure at the foot of Mount Hood, the lava first poured down the valley in a single, broad stream, pushing the Middle Fork of the Hood River from its channel.
As the river of molten rock reached the flats of the upper Hood River Valley, the lava began to spread out from the river channel, with great lobes spilling sideways from the main flow onto the valley floor. By the time the eruption was over, the lava had traveled more than four miles, and poured more than 390 million cubic yards of molten rock on the surface. That’s 4 million dump truck loads of lava, and when the lava cooled, it covered nearly 3,000 acres to depths as much as 300 feet.
The Middle Fork of the Hood River must have been a hellish sight when the eruption occurred, as molten rock filled the stream bed, and vaporized both river and forest as it overwhelmed the landscape. Today, the river traces the west margin of the flow (shown on the right in the image above), with lava slopes rising steeply from the stream. This rugged terrain along the Middle Fork makes for one of the least-visited sections of river anywhere in the Mount Hood region.
The Parkdale Lava Flow is young by geologic standards at just 7,000 years old. That places the eruption at about the time when Crater Lake was formed, following the massive eruption and collapse of the former Mount Mazama.
Geologists note that the Parkdale flow overlays traces of Crater Lake ash deposited in the Mount Hood area, suggesting that the lava flowed just after the destruction of Mount Mazama. This puts both events within the period when the first Native Americans were living in the region, and we can only imagine how the ensuing chaos must have impacted these early residents.
Since the eruption 7,000 years ago, a few trees have pioneered the lava flow, mostly along shaded side slopes, but it mostly looks like it erupted very recently. As might be expected, the flow is also home to small wildlife that thrive in the shelter that the jumbled rock provides. Through sheer luck, the flow was never mined for aggregate, despite its proximity to huge construction projects, such as the dams and highways in the nearby Columbia River Gorge.
The Forest Service has designated 854 acres of the Parkdale Lava Flow as a geologic “Special Interest Area” for the stated purpose of “public recreation use, study and enjoyment.” In its forest plan, the agency has committed to managing such areas in a natural condition, pending a detailed implementation plan for each area. This is where the Parkdale Lava Flow stands today.
Part of the lava flow, along the northeast corner (see map), is on private land. While this private land is already inside the Mount Hood National Forest jurisdictional boundary, the agency rarely acquires land thanks to lack of dedicated funding or a clear mission on which lands ought to be acquired. So for now, this is yet another unique natural feature at risk of development.
In the long term, the Mount Hood National Park Campaign envisions bringing the L-shaped piece of private land into public ownership, and providing recreational and interpretive access to the area. Until that day, the area can be explored off-trail, with access from adjacent forest roads.