A Gust erosion chamber was used to apply horizontal shear stress to sediment cores obtained from San Pablo and Grizzly (within Suisun) Bays in California. A pair of sediment cores were collected from the same approximate locations in each bay six times between June 12th, 2019 and August 15th, 2019 for a total of 12 experiments and 24 sediment core results. Locations were chosen to capture the benthic variability along the estuarine salinity gradient, are established benthic monitoring stations, proximity to historic/restored wetlands, and practicality for field operations. Sampling dates targeted spring and neap tide conditions. An onshore experiment was conducted on each core to apply shear stresses with stepwise and monotonic increases. Effluent following erosion was monitored for turbidity and sampled for suspended-sediment concentration analysis. For each core, experiment results were used to calculate the following at each applied shear stress step of the experiment: 1) critical shear stress required to initiate erosion, 2) mass eroded per square meter, and 3) the erosion rate coefficient (M). Equations used for calculations are outlined in Process Step 3 of this data release. Erosion experiments were successful for six core pairs from San Pablo Bay and six core pairs from Grizzly Bay, with initial critical shear stresses ranging 0.030 to 0.075 Pa and erosion rate coefficients ranging 2.1e-05 to 2.1e-03 kg/(m^2*s^1*Pa).