Protecting Agricultural Spaces Through Effective Ranching Strategies Act or the PASTURES ActThis bill prohibits the Department of Agriculture (USDA) and the Department of the Interior from imposing penalties on livestock owners for grazing on certain public lands. Under the bill, covered lands are National Forest System lands, lands administered by the U.S. Fish and Wildlife Service, or public lands (1) on which grazing is allowed by a permit or lease on or after the date of the bill's enactment and is then subsequently prohibited, and (2) that border private property.Specifically, the departments may not impose a penalty on an owner of livestock (including cattle, bison, horses, sheep, and goats) for grazing on covered lands that do not have a fence to prevent grazing.The bill specifies that USDA or Interior, depending on the covered land, is responsible for any expense related to the construction or maintenance of a fence for the prevention of grazing by livestock.