Federal Lands Improvement Act of 2003

Federal Lands Improvement Act of 2003 - Directs the Secretary of the Interior to dispose of all public lands administered by the Bureau of Land Management (BLM) that, as of the enactment date of this Act, have been identified for disposal under the Federal land use planning process under the Federal Land Policy and Management Act of 1976. Requires the disposal of at least one- third of such lands before the end of the next three years, two-thirds before the end of the next five years, and all such lands within seven years.

Prohibits the disposal of: (1) lands located in wilderness areas or wilderness study areas; and (2) parcels of land if the cost of disposal exceeds the amount that would be received for such parcels.

Requires the disposal of such public lands in parcels of 160 acres or less.

Requires one-third of the proceeds to be deposited in a separate account established by this Act, one-third to be paid to the county in which the lands are located, and one-third to be deposited in the Treasury's general fund and utilized for reducing the public debt. Requires the separate account to be available to the Secretary for paying, subject to specified limitations: (1) costs incurred by the BLM in arranging the disposals; (2) the cost of acquisition from a willing seller of environmentally sensitive land in States in which such public lands are located; (3) the cost of carrying out any necessary revision or amendment of a current BLM land use plan that relates to such public lands; (4) the cost of projects or programs to restore or protect wetlands, riparian areas, or cultural, historic, prehistoric, or paleontological resources on public lands, including petroglyphs; and (5) the cost of projects, programs, or land acquisition to stabilize or restore water quality for water located or used on public lands.