Backcountry Landing Strip Access Act - Prohibits the Secretary of the Interior and the Secretary of Agriculture from taking any action that would permanently close, restrict, render or declare as unserviceable any aircraft landing strip located on federal land under their respective jurisdiction, unless: (1) the head of the aviation department of each state in which the aircraft landing strip is located approves the action; (2) notice of the proposed action has been published in the Federal Register; (3) a public comment period on the action has been provided; and (4) the relevant Secretary and the head of the aviation department of each state in which the affected aircraft landing strip is located have taken into consideration any comments received during the comment period.

Directs the Secretaries to: (1) adopt a nationwide policy for governing backcountry aviation issues related to the management of federal land under their jurisdiction; and (2) require regional managers to adhere to it. Declares that a policy affecting air access to an aircraft landing strip located on federal land will not take effect unless certain conditions are met.