To provide for an exchange of lands with the city of Greeley, Colorado, and The Water Supply and Storage Company to eliminate private inholdings in wilderness areas, and for other purposes.

Directs the Secretary of Agriculture to transfer specified Federal lands to the city of Greeley, Colorado, and The Water Supply and Storage Company, a Colorado mutual ditch company, if the city and the company offer to transfer specified lands to the United States (Rockwell Ranch and Timberline Lake properties and specified company lands).

Specifies exchange terms and conditions, including that: (1) the United States shall grant perpetual access easements to the city and the company to the lands conveyed; (2) the city and the company shall continue to make specified reservoirs accessible to visitors to the Roosevelt National Forest; (3) all special use permits, easements, or other instruments authorizing occupancy of certain identified Federal lands are rescinded; and (4) conditions specified in certain easements for Long Draw, Peterson Lake, and Barnes Meadow Reservoirs requiring a joint operations plan providing instream winter flows to the mainstream of the Cache La Poudre River from Chambers Lake and Barnes Meadow Reservoir shall continue to be fulfilled regardless of land ownership unless the grantor and grantee of an easement agree otherwise.

Directs that lands acquired by the United States under this Act be added to and administered as part of the Roosevelt National Forest and the portions of such lands located within a wilderness area shall be added to such area.

Modifies the boundaries of the Arapaho and Roosevelt National Forests.