Models for the assembly of the Arctic Alaska−Chukotka microplate suggest the juxtaposition of Laurentia- and Baltica-affinity terranes in the mid-Paleozoic. Subsequently, the Arctic Alaska−Chukotka microplate moved southward during the Mesozoic opening of the Amerasia Basin, approaching its present position. To refine these models, this study presents data on the provenance of rocks from the metamorphic core of the southern Brooks Range, elucidating the location of the Arctic Alaska−Chukotka microplate and its composite pre-Mississippian terranes during periods of Arctic tectonic reorganization. The recycling of Tonian−Ediacaran sedimentary and igneous rocks from the southern Arctic Alaska−Chukotka terrane and Arctic Russia across an Ediacaran to Cambrian unconformity, which developed after the Timanian orogeny, restores the southern Arctic Alaska−Chukotka terrane to the northern margin of Baltica during the Precambrian−Cambrian. A pre−Middle Devonian unconformity across Arctic Alaska is recorded in rift-related Middle Devonian to Mississippian(?) sediments. Erosion of genetically unrelated pre−Middle Devonian basement units and mixing of their detritus into localized Middle Devonian and younger rift basins confirm the presence of a major Paleozoic suture in the Arctic Alaska−Chukotka microplate, related to the Caledonain-aged deformation, that juxtaposed Laurentian, Baltican, and isolated intra-Iapetan magmatic arc−affinity terranes. Similar age spectra in Late Devonian sedimentary rocks from Arctic Alaska and Arctic Canada support models proposing that the Arctic Alaska segment of the Arctic Alaska−Chukotka microplate restores to the northern margin of Laurentia prior to the opening of the Amerasia Basin. The contact of pre-Mississippian terranes in Arctic Alaska supports a two-part opening model for the Amerasia Basin, restoring Arctic Alaska to an along-strike position with a correlative suture exposed in northernmost Ellesmere Island, Canada, by a rotational component linked to the opening of the Canada Basin together with a phase of opening perpendicular to the Lomonosov Ridge to restore the Chukotka portion of the Arctic Alaska−Chukotka microplate to the Lomonosov Ridge and northern margin of Baltica.