This dataset provides estimates of soil active layer thickness (ALT) at 30-m resolution derived by combining overlapping airborne L-band synthetic aperture radar (SAR) soil seasonal subsidence and P-band SAR soil moisture data through the remotely-sensed active layer thickness (ReSALT) algorithm for 12 study areas across Northern Alaska. The airborne data collection occurred from 2017-06-19 to 2017-09-16 on a coincident grid of flight lines with the 2017 aircraft campaign for the Arctic Boreal Vulnerability Experiment (ABoVE). Concurrently collected data including the L-band soil seasonal subsidence and the P-band soil dielectric constant and volumetric water content are provided. Calculated uncertainties for all variables are also provided.