Much of the Atlantic coast of North America has been sinking for thousands of years, at a maximum rate of ~20 cm per century, due to solid Earth deformation in response to deglaciation of the Laurentide ice sheet – a process known as glacial isostatic adjustment (GIA). In addition to GIA, other factors, including recent human intervention in water sources (such as excessive groundwater usage and damming) might be significant contributors to vertical land motion (VLM) in the region. The primary aim of this research is to isolate and better understand the contributions of these processes to VLM in southeastern Canada and northeastern USA. To this end, we use results from an extensive GIA modelling analysis based on a large ensemble of 14,960 Earth-ice model input parameters and two regional paleo RSL data compilations, as well as millennial-scale VLM rates derived from RSL reconstructions, to determine if contemporary VLM rates determined from the Global Navigation Satellite System (GNSS) deviate from the longer-term millennial-scale trend. Preliminary results indicate that there are regions whether the contemporary and paleo rates are significantly different and we will report on efforts to explain these residual signals. To complement our GIA and GNSS analyses, we will use satellite gravity (GRACE) observations to determine whether the VLM rate residuals are compatible with contemporary mass redistribution signals.