Summary: The Annual Brome Adaptive Management (ABAM) decision support tool (DST) was built to support vegetation management decision making, particularly regarding invasive annual brome grasses, of seven National Park Service units (“parks”) in the Northern Great Plains. The ABAM DST is a state-transition Bayesian network based on scientific literature and 20 years of vegetation monitoring in those parks. In each year of an adaptive management cycle, the DST is updated with recent monitoring data, then used to quantify the state of the vegetation in each park management unit, compare the predicted outcomes of 10 different management actions for each of those units, and determine the optimal management action for the next year according to park managers’ relative acceptance of different vegetation states. Management actions include no action, fall or spring fire, application of germination-inhibiting herbicides, and combinations of fire and those herbicides. Implementation of the ABAM framework and use of the DST in that framework began in 2021. This talk will describe the decision support tool and how it is being used by parks.