Interpretation of a 75 kilometre-long cross-section in the foothills of northeastern British Columbia near latitude 55 degrees 30＇N is interpreted to show shortening that is compartmentalized by several pairs of floor and roof detachments. Observations of tectonic thickening that is localized stratigraphically can be seen in surface geology and well penetrations and can be inferred from seismic reflection images. There are significant detachments interpreted for five specific stratigraphic intervals: 1) Middle Paleozoic, 2) Lower Triassic, 3) Jurassic, 4) Lower Cretaceous, and 5) upper Lower Cretaceous. Ramping thrust faults and/or detachment folds are interpreted to be confined between a basal and an upper detachment. In contrast to the southern Alberta Foothills, there is an absence of large reverse-separations suggesting that hanging-wall thrust ramps do not typically breach upper detachments in the northeastern British Columbia Foothills. Palinspastic restoration of the cross-section shows sequentially greater amounts of shortening above successively higher detachments. Sense of shear on and between detachments is predominately towards the foreland (northeast). In 1985, McMechan inferred the presence of a low-angle taper triangle zone extending across the entire northeastern British Columbia Foothills Belt to explain a cross-section interpretation showing lesser Mesozoic-level shortening above greater Paleozoic-level shortening. A hinterland-vergent decollement was necessary in the Lower Triassic. With the advantage of subsequent exploration drilling, seismic profiling and surface mapping, interpretation of much greater shortening within Mesozoic strata is now possible. The greater shortening at Mesozoic levels restricts the space available for inferred shortening in Paleozoic rocks. If the Paleozoic-level shortening is indeed less than that occurring in the Mesozoic, as has been interpreted here, vergence on the Lower Triassic detachment must be foreland-vergent.