We apply dynamic local B0 field control with a multi-coil (MC) shim array to improve ASL labeling. Labeling efficiency can be regulated by dynamically shimming the labeling plane during a pCASL tagging pulse train. We demonstrate this capability through territory mapping with an unspecialized MC head shim array – Through shimming, we shift target arteries relative to the labeling pulse bandwidth. Implementation takes less than 10 minutes during a scan, without previous subject information. We also simulate the improvement possible with a specialized MC neck shim array, which enables regulation in more inferior labeling planes and higher field control efficiency.