In the home stretch of its more than 1,000 mile-long journey from the Canadian Rockies to the Pacific Ocean, the Columbia River has carved a spectacular canyon that now forms the border between Oregon and Washington: the Columbia River Gorge. Nearly 100 miles in length, the Columbia River Gorge is one of the most unique landscapes in the Pacific Northwest, and home to some spectacular geology. Most of the gorge is carved into the Columbia River Basalts, layers upon layers of volcanic rock formed by vast lava flows that inundated most of central and eastern Washington about 16 million years ago. More recently, a series of large glacial outburst floods at the end of the last ice age broadened and re-shaped the gorge as they raged their way down the Columbia River to the Pacific Ocean, creating many of the landforms that we see today.
By the time the Columbia River enters the gorge, its elevation has already dropped to just 160 feet above sea level. The low elevation of the gorge makes it one of the warmest areas in the Pacific Northwest, and a prime destination for some early season camping. We recently spent three days in the Columbia River Gorge soaking up what passes for balmy weather this time of year around here.
Two of the main attractions in the Columbia River Gorge are wildflowers and waterfalls. Even now, in mid-to-late March, the wildflower show was already in full swing, particularly in the drier, warmer, eastern reaches of the gorge:
One of the most remarkable sights in the Columbia River Gorge is experiencing the rapid change in environment as you drive through the gorge from east to west. The Dalles, located near the eastern end of the gorge, lies in the rain shadow of the Cascade Range and receives very little precipitation: just 14 inches annually. Here, the rocky slopes of the gorge are nearly devoid of any vegetation other than wildflowers and grasses. Just half an hour and a handful of freeway exists to the west, the average annual precipitation has increased to about 30 inches at Hood River, and ponderosa pine and Douglas fir cover the slopes. 20 more miles/minutes to the west, at Cascade Locks, annual precipitation rises to over 75 inches and the gorge is filled with the dense, shady, and mossy forests typically associated with the Pacific Northwest. In other words, you can travel from a true desert to a near-rainforest in less than an hour, while driving on a nearly flat interstate that hugs the shore of massive reservoirs created by dams along the lower Columbia River.
The combination of dramatic terrain and copious precipitation at the western end of the Columbia River Gorge (particularly on the more mountainous Oregon side) combines to form some of the most spectacular waterfalls in the United States. As the aforementioned ice age floods flowed through the gorge on their way to the Pacific, they removed the lower ends of valleys belonging to the Columbia’s many tributary streams. Consequently, many of these tributaries enter the gorge several hundred feet above river level, terminating in spectacular plunges that carry their water into the Columbia River:
Let’s be clear: with temperatures in the 40s and 50s and the nearly constant winds that blow through the gorge, it was no spring break in Florida, but after a long winter and with the Cascades still buried in snow for several more months, the greenery and signs of spring were a welcome sight. (Even though we did have our tent totally chewed up by an unknown animal…a first for us in many, many nights of camping throughout the west!)