Lewis and Clark National Historical Park Act of 2004 - Establishes the Lewis and Clark National Historical Park in the States of Washington and Oregon as a unit of the National Park System.
Requires the Secretary of the Interior, subject to valid rights (including withdrawals), to transfer to the Director of the National Park Service management of any Federal land at Cape Disappointment, Washington, that is within the boundary of the Park.
Revokes withdrawals of the 20-acre parcel depicted on the map as "Memorial to Thomas Jefferson." Directs the Secretary to establish a memorial to Thomas Jefferson.
Authorizes appropriations.