imnaha moonset

Imnaha Moonset

Looking southwest across the chasm of the Imnaha River with the moon dropping below the snowy peaks of Oregon's Wallowa Mountains at sunrise. The layer cake of basalt lava flows exposed in the Imnaha Canyon are part of the enormous Columbia River Basalt Formation which poured out of the ground repeatedly from about 16 to 14 million years ago and flowed three hundred miles to the Pacific Ocean, along the way inundating much of eastern Oregon and Washington not to mention a significant area in western Oregon and Washington as well. People living in such far flung towns as Spokane, Wenatchee, La Grande, Portland, Lewiston, Pendleton, The Dalles, Astoria, Cannon Beach, McMinnville, and Chehalis can be forgiven if they grow up assuming erroneously that the whole world is made of basalt. It was here in northeast Oregon that much of this lava was erupted, prompting some geologists to refer to it as "The Grande Ronde Volcano" or "Chief Joseph Dike Swarm." "Imna" was the name of a legendary Nez Perce Indian chief and "Imnaha" means "Land of Imna." Photographed on 4x5.

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