A multidisciplinary study of crustal movements in coastal Maine has shown that parts of the state's coastal zone are subsiding. This subsidence is associated with seismic activity that has persisted locally since at least the 1800s. Bedrock structural studies have not produced evidence of major Holocene faulting, but measured horizontal rock strains may be related to Mesozoic graben development in the adjacent Gulf of Maine. The crustal down warping is most apparent in eastern Maine, where releveling data indicate a modern subsidence rate of as much as 9 mm/yr. The anomalously rapid sea-level rise resulting from this subsidence has caused erosion and submergence of archeological sites and historical man-made structures. However, the altitudes of glaciomarine deltas and the distribution of dated archeological sites show that the present subsidence rates have not persisted throughout Holocene time.