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About the Image

The "Hooker Oak" was named in honor of Sir Joseph Dalton Hooker of the Royal Botanic Gardens at Kew on the occasion of Hooker’s visit to Chico, California, in 1887 by Annie Bidwell, a prominent local benefactor. It was the largest valley oak (Quercus lobata Nee) of its day, although it is purported to have been composed of two fused trees, The "tree" was estimated to be 326 years old (measuring 32 m in height with a basal circumference of 8.5 m) when it fell during a violent windstorm on 1 May 1977. A plaque commemorates the site of the tree’s trunk, which is an officially designated California State monument. The proximate causes of tree mechanical failure are manifold. They include static instabilities resulting from wood rot, disproportionate crown growth with respect to root anchorage, and wind-induced stem flexure. Inspection of period photographs and the surviving remnant of the trunk-base suggests that the Hooker Oak experienced dynamic drag-induced instability at its trunk-root junction, resulting in local fracturing and catastrophic shear failure.