DescriptionPrecarious boulders are peculiar naturally occurring geological formations that showcase large rocks resting on another rock. This particular balanced rock rests upon a small slope overlooking Omak Lake on the Colville Indian Reservation in Washington. The 1.3 million acre reserve is also home to several other balancing phenomena. The surrounding area is largely cheat grass and sagebrush with a few rolling hills.
The balancing rock at the south end of Omak Lakerock is made of homogenous granite, with a porphyritic texture (Weichert, 1994). The massive boulder weighs in at approximately forty tons and balances on a much smaller foundation that is only fractional in comparison to its counterpart. The understructure is also made of granite from the Cretacesous Boot Mountain plutonic complex (WA DNR, 2016), but is finer grained, less porphyritic, and overall more mafic (Weichert, 1994). The weight of the rock is distributed relatively even (Weichert, 1994). The rocks are not fixed together in any fashion and there appears to be small windows of erosion between the differing forms.
The massive stone is thought to be an erratic carried in by glacial action from up north. The large chunk of granite is consistent with a proximate Canadian quarry (Weichert, 1994). The Omak erratic also resembles a hoodoo which is a pillar of a rock shaped extraordinarily by erosion (dictionary.com).
Omak rock is controversially considered the epicenter of a 7.5 magnitude earthquake on December 14, 1872. This is one of the greatest known trembles in the Pacific Northwest (Weichert, 1994). Some experts believe it had to have been at the epicenter because it could have not weathered such a jolt intact. Other scientists believe that mathematics prove the balanced rock could have withstood such tremors if the epicenter was in Chelan, WA positioned about 90 km southwest of Omak rock (Weichert, 1994).
The Colville tribe has no known legends or coyote stories involving the rock and believe it is simply a representation of nature’s splendor (colvilletribes.com).