Free air, Bouguer, and isostatic anomalies are listed in a table of principal facts for 23 stations established by the Dominion Observatory in the area between latitudes 55 and 70 degrees, bounded on the east by Hudson Bay and on the west by Athabaska, Slave, and Mackenzie rivers. There is some evidence that the predominantly negative anomalies at stations in the Pre-Cambrian may be due to lack of isostatic adjustment following removal of glacial loads.