Upper Triassic volcanogenic rocks of the Seven Devils Groups and Huntington Formation of Brooks (1976b) in northeastern Oregon record two episodes of magnetization. The older magnetization, which predates Late Jurassic deformation of the volcanic arc terrane comprising the Seven Devils Group, was probably acquired in Late Triassic time. The inclinations of both normal and reversed polarity magnetizations indicate that the Triassic rocks originated approximately 18¿ from the paleoequator. The results are consistent with paleomagnetic data from similar Triassic rock assemblages on Vancouer Island and in south central Alaska. We interpret these assemblages as displaced fragments of Wrangellia, a once coherent late Paleozoic volcanic arc and early Mesozoic volcanic plateau that was torn apart and carried north by plate motion along the continental margin. We interpret the younger magnetization, which fails the fold test, as a widespread thermochemical overprint caused by Late Jurassic and Early Cretaceous plutonism. This magnetization yields a paleomagnetic pole at 60¿N, 295¿E (α95=7¿), and is similar to the pole obtained from plutons that intrude the Seven Devils Group. The angular difference between the pole from the plutons and the Late Jurassic-Early Cretaceous reference pole for stable North America suggests that the Seven Devils volcanic arc has undergone a large clockwise rotation (66¿¿21¿). The rotation may reflect the last stages of the arc's accretion to the continental margin or later large-scale block movements in the Pacific northwest.