  Vector Dark Matter (VDM) that couples to lepton flavor ($L_e$, $L_{\mu}$,
$L_{\tau}$) acts similarly to a chemical potential for the neutrino flavor
eigenstates and modifies neutrino oscillations. VDM imparts unique signatures
such as time and directional dependence with longer baselines giving better
sensitivity. We use the non-observation of such a signal at Super-Kamiokande to
rule out the existence of VDM in a region of parameter space several orders of
magnitude beyond other constraints and show the projected reach of future
experiments such as DUNE.
