The dataset in this issue of Nordicana D comprises data collected remotely using LiDAR elevation data in the St. Lawrence Lowlands area (i.e., Québec, Ontario, Vermont, New-York State). It contains the location of beach ridges associated with the maximal extent of the Champlain Sea (11,100 to 9,400 years BP), a post-glacial sea that inundated the area following the retreat of the Laurentides Ice Sheet, the inlandsis that covered much of North America during the most recent glacial period (i.e., Late Wisconsinan). The dataset also contains locations of beach ridges associated with stages of isostatically-driven marine regression of that same sea. Beach ridges were identified remotely using relief shading models (RSMs) derived from 52000 km2 of high-resolution LiDAR DEMs obtained from publicly available American and Canadian sources (i.e., MFFP and USGS). For each beach ridge section delineated, we provide the longitude, latitude, beach ID, section ID, length of the section, minimal elevation of the ridge, mean elevation of the ridge, maximal elevation of the ridge, and a map showing the location of the section with regard to local topography (i.e., RSM). We also state if the beach ridge is associated to the maximal extent or to a regressive stage of the Champlain Sea.