Despite the importance of channel avulsion in constructing fluvial stratigraphy, it is unclear how contrasting avulsion processes are reflected instratigraphic-stacking patterns of channelized fluvial sandbodies, asa proxy for how riverdepocentersshifted in time and space. Using an integrated, geospatially-referenced 3D dataset that includesoutcrop, core, and LiDAR data, we identify for the first time in an outcropstudy a predictive relationship between channelized-sandbodyarchitecture, paleochannel mobility, and stratigraphic-stacking pattern. Single-story sandbodies tend to occur in vertically-stacked clusters that are capped by a multilateral sandbody, indicating an upward change from a fixed-channelsystem to a mobile-hannelsystem in each cluster.Vertical sandbody stacking in the clusters implies reoccupation of abandoned channelsafter “local” avulsion.Reoccupational avulsion may reflect channel confinement, location downstream of a nodal avulsion point that maintained its position during development of the sandbody cluster, and/or aggradation and progradation of a backwater-mediated channel downstream of a nodal avulsion point. Sandbody clusters and additional multilateral sandbodies are laterallyoffset or isolated from each other, implying compensational stackingdue to “regional” switching of a nodal avulsion point to anew, topographically-lowersite on the floodplain.The predictive links between avulsion mechanisms, channel mobility,and resultant sandbody distributions and stacking patterns shown in our findings haveimportant implications forexploringand interpreting spatio-temporal patterns of stratigraphic organizationin alluvial basins.