Our understanding of how sensorimotor information is integrated across dendritic trees is limited by our ability to image these distributed 3D structures in awake animals. We overcome the existing limitations of rapidly measuring 3D dendritic activity and avoiding signal distortion by brain motion artefacts by utilizing our novel nonlinear 3D acousto-optic lens two-photon microscope with real-time 3D brain motion correction and innovative Ca2+ imaging analysis pipelines. This enable the study of sensorimotor information representation in dendritic activity patterns of awake mice during natural behaviors. We imaged layer 2/3 neurons of primary motor cortex, a representationally rich sensorimotor integration hub that plays a key role in modulating primitive movements like locomotion and whisking. Consistent with previous work, we found that a strong, highly correlated cell-wide Ca2+ signal is the dominant activation mode in vivo. We find independent branch-specific local events are rare, and when observed, are largely accounted for by contaminating signals. Applying nonlinear dimensionality reduction techniques to the global signals, we discovered specific dendritic regions that covary with uninstructed spontaneous movements. These modulations (spread over >20 μm compartments) were superimposed on the global signals. Dendritic modulations were dynamic across behavioral epochs including quiet-rest, exploration, active whisker touch, and unexpected sensory surprise. Remarkably, regression analyses suggest that these modulations in the activity of dendritic segments are more informative about specific behaviors than the activity at the soma in the majority of cells. Our results indicate that L2/3 pyramidal cell dendritic activity patterns are multidimensional and represent several innate behavioral features simultaneously.