Fresh volcanic eruption deposits tend to be loose, bare, and readily resuspended by wind. Major resuspension events in Patagonia, Iceland, and Alaska have lofted ash clouds with potential to impact aircraft, infrastructure, and downwind communities. However, poor constraints on this resuspension process limit our ability to model this phenomenon. Here, we present laboratory experiments measuring threshold shear velocities and emission rates of resuspended ash under different environmental conditions, including relative humidity of 25-75% and simulated rainfall with subsequent drying. Eruption deposits were replicated using ash collected from two major eruptions: the 18 May 1980 eruption of Mount St. Helens and the 1912 eruption of Novarupta, in Alaska's Valley of Ten Thousand Smokes. Samples were conditioned in a laboratory chamber and prepared with bulk deposit densities of 1,300-1,500 kg/m(3). A control sample of dune sand was included for comparison. The deposits were subjected to different wind speeds using a modified PI-SWERL (R) instrument. Under a constant relative humidity of 50% and shear velocities 0.4-0.8 m/s, PM10 emission by resuspension ranged from 10 to >100 mg.m(-2.)s(-1). Addition of liquid water equivalent to 5 mm of rainfall had little lasting effect on Mount St. Helens wind erosion potential, while the Valley of Ten Thousand Smokes deposits exhibited lower emissions for at least 12 days. The results indicate that particle resuspension due to wind erosion from ash deposits potentially exceeds that of most desert surfaces and approaches some of the highest emissions ever measured. Plain Language Summary Immediately after a volcanic eruption, freshly deposited ash can be lifted by wind similar to how dust is suspended by wind in arid regions. These resuspended ash particles are smaller than the original, more clumpy material that fell during the eruption and are abundant enough to impact human health, visibility, and industrial processes. This is known to happen because it has been observed in the field, but there has been little direct measurement of how much ash can be resuspended at various wind speeds. In the present study, we used a small wind tunnel-like device (PI-SWERL) to measure resuspension of ash. Samples were collected from two locations: the Valley of Ten Thousand Smokes in Alaska (site of the 1912 Novarupta eruption) and deposits from the Mount St. Helens 1980 eruption. The potential for resuspension was measured at multiple simulated wind speed equivalents and under several conditions of atmospheric humidity. Overall, it was found that the Valley of Ten Thousand Smokes samples were more influenced by atmospheric humidity as well as the presence of liquid water a few centimeters below the surface than the Mount St. Helens samples. The latter exhibited the potential for extremely high resuspension rates, approaching the highest that have ever been measured for arid soil surfaces. Vegetation, compaction over time, and other environmental processes likely have a large role in reducing what would otherwise be extraordinary emissions of ash for weeks to years following a volcanic eruption.