Continental magnetic anomaly patterns are interrupted by east‐west features similar to, though less obvious than, those found in the East Pacific. The distribution of these east‐west interruptions in aeromagnetic surveys of parts of the U.S.A. has been analyzed quantitatively. Evidence of persistence of E‐W interruptions across individual surveys for distances of more than 100 miles is presented. By comparing surveys at different longitudes but at the same latitude, it is shown that certain interruptions continue for greater distances. For example, the Mendocino feature of the East Pacific can be traced unmistakably through surveys in California to eastern Nevada, and appears to be present in eastern Colorado. By analogy with the East Pacific studies, the magnetic features are interpreted as the expression of a pattern of fractures. However, there is no evidence of consistent offset comparable with that found in the East Pacific. The fractures are considered to be deep and partly decoupled from the upper reaches of the crust, so that they are clearly recognized in the thin oceanic crust but are partly masked by local shallow complexities in the continental crust.