Collective cell migration in fibrous extracellular matrix (ECM) is crucial to many physiological and pathological processes. Migrating cells generate active pulling forces by actomyosin contraction, which are transmitted to the ECM via focal adhesion complexes and remodel the ECM, leading to the formation of mesoscale structures such as fiber bundles “bridging” the cells. The role of such mesoscale structures in transmitting active tensile forces generated by contractile cells and in regulating collective multi-cellular migratory behaviors remains to be clarified. This talk introduces our recent theoretical and experimental investigations on how the remodeled fiber bundles may regulate cell migration and correlated multi-cellular dynamics.