U.S. National Arboretum Appreciation Act of 2004 - Requires the Secretary of Agriculture to enter into a contract with the Friends of the National Arboretum, either through a sole-source contract or other method, to authorize the Friends of the National Arboretum to act as agent of the Department of Agriculture to: (1) allow the use of the grounds and facilities of the National Arboretum by private persons and entities; (2) provide services related to planning and overseeing special events there; and (3) make such other arrangements as appropriate for its private use.
Authorizes the Secretary to enter into contracts with other persons or entities for private use of such grounds and facilities so long as the contracts do not conflict with the contract with the Friends of the National Arboretum.