National Wildlife Refuge System Improvement Act of 1997

National Wildlife Refuge System Improvement Act of 1997 - Amends the National Wildlife Refuge System Administration Act of 1966 to: (1) add definitions of "compatible use," "conserving," "Coordination Area," and other terms; and (2) set forth the overall mission and enumerate the specific purposes of the National Wildlife Refuge System. Adds a requirement that in administering the System the Secretary of the Interior shall ensure that such mission and purposes are carried out, except that if a conflict exists between the purposes of a refuge and any purpose of the System it shall be resolved in a manner that first protects the purposes of the refuge.

Authorizes the Secretary to enter into agreements with State fish and wildlife agencies, which are subject to standards by and management oversight of the Director of the U.S. Fish and Wildlife Service, for the management of programs on a refuge, or the management of parts of a refuge.

States that, with specified exceptions, three years following enactment of this Act, the Secretary shall not initiate nor permit a new use of a refuge or an expansion of an existing refuge unless it is a compatible use.

Establishes compatibility standards and procedures, including those for fishing and hunting. Requires the Secretary to issue final regulations establishing the process for determining a compatible use.

Sets forth the activities relating to overflights above a refuge and Federal agency usage under which the compatibility determinations shall not apply and conditions that overflights above a refuge may be governed by any memorandum of understanding entered into by the Secretary that applies to the refuge.

Directs the Secretary to propose comprehensive conservation plans for each refuge in the System, except those lands in Alaska (which shall be governed by the Alaska National Interest Lands Conservation Act). Requires maximum 15-year cycles of plan revision. Sets forth the matters to be considered in plan development, including wildlife migration patterns, plant populations, archaeological values, habitat problems, and recreational opportunities.

Permits temporary suspension of any refuge activities in emergencies that constitute an imminent danger to the public or any fish or wildlife population, including any activity to control or eradicate sea lampreys, zebra mussels, or any other aquatic nuisance species.