National Park Preservation Act - Requires the Secretary of the Interior to deposit in a separate account of the Treasury of $500 million in Outer Continental Shelf revenues from oil and natural gas production during each fiscal year, which shall, without further Act of appropriation, be available to the Secretary in subsequent fiscal years until expended.

Makes such funds available for expenditure in units of the National Park System (NPS) that have ecosystems, critical habitat, cultural resources, or other core park resources that are threatened or impaired. Allocates 30 percent of funds to NPS units threatened or impaired by activities occurring inside the unit, and 70 percent to units threatened or impaired by activities occurring outside the unit. Specifies an annual amount for FY 2000 through 2015 for the Federal share (50 percent) of the Everglades and South Florida ecosystem restoration project under the Water Resources Development Act of 1996.

Prohibits from deposit in the separate account any revenues from any new oil and gas leases, or from development of any existing leases in a moratorium area.