A first-time visitor to the Tri-Cities or any town in Eastern Washington – might notice the various sizes of perfectly shaped, elongated, hexagonal, brownish rocks standing upright in landscaping works. Often staggered adjacent to one another, these harvested basaltic columns are commonly arranged in an attempt to duplicate the outcrops found throughout southeastern Washington, northeastern Oregon, and east central Idaho.


Basalt is an igneous rock that solidified from many eruptive lava flows that covered the northwest and formed what is now known as the Columbia Plateau, filling the area between the Cascades and the Rockies. Many of these massive lava lakes cooled from the top down. Furthermore, under the right conditions, the rate of cooling would allow cracks to form — usually hexagonal or octagonal in shape — which can range from 10 cm to three meters in diameter. These cracks could grow vertically downward, sometimes to a depth of around 80 ft. One can find many examples of these cracks in colonnade formations while traveling down the Columbia River toward Portland, Oregon, through the Columbia Gorge. Another excellent site is the Palisades overlook on the White Pass Scenic Pass Byway. Closer to the Tri-Cities, the Palouse Falls and Twin Sisters in Wallula Gap provide excellent exhibits of these columnar structures.


As far as planting some of these columns as a landscaping focus, a person needs to decide how and where to use them. There are virtually unlimited ways to put these rocks to creative use. They could become ready-made steps, benches, or seats around a firepit. Furthermore, two could support a wooden bench seat. You can find a variety of pre-bored columns for making a fountain or a bubbling birdbath. Water features could be enhanced with well-placed columns. There are even some interior applications that might add an interesting and useful focus. However, it’s ultimately up to you to make these formations your own!

Where can you find these columnar gems? First, pay a visit to some local nurseries to see what they might offer. You can read our article about local nurseries here. Another productive stop would be Eagle Rock, LLC. They are located just off of Reata Rd. in south Richland. Bedrock Specialty Stone Products at 9201 W. Hildebrand Rd., Kennewick is also a good choice. Both have a wide selection of rocks from which to choose. Bedrock also offers stone engraving in small and large basalt specimens at a fair price.


Finally, never rule out rock collecting; there are many areas in southeastern Washington where smaller columnar rocks can be procured. With a pickup or a trailer, gloves, and a couple of strong friends, it is feasible to pick up smaller columnar segments to enhance a project. Basalt is a natural part of our region’s geology and can complement your landscaping work.

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