Spring Basin Wilderness Act of 2008

Spring Basin Wilderness Act of 2008 - Designates certain Bureau of Land Management (BLM) land in Oregon as wilderness and as a component of the National Wilderness Preservation System, to be known as the Spring Basin Wilderness. Requires any land or interest within the boundary of the Wilderness acquired by the United States to become part of such Wilderness.

Permits established livestock grazing in the Wilderness to continue.

(Sec. 4) Releases specified portions of the Spring Basin wilderness study area that are not designated as the Spring Basin Wilderness by this Act from further study for designation for preservation as wilderness.

(Sec. 5) Provides for the following land exchanges in Oregon: (1) the Confederated Tribes of the Warm Springs Indian Reservation land exchange; (2) the McGreer land exchange; (3) the Keys land exchange; and (4) the Bowerman land exchange.

Withdraws the non-federal land acquired by the Secretary of the Interior from the Confederated Tribes of the Warm Springs Reservation from all forms of: (1) entry, appropriation, or disposal under the public land laws; (2) location, entry, and patent, under the mining laws; and (3) disposition under any law relating to mineral and geothermal leasing or mineral materials.

Sets forth requirements for the valuation, appraisal, and equalization of the federal and non-federal lands to be exchanged under this section.

Requires any cash equalization payments received by the Secretary to be deposited in the Federal Land Disposal Account established by the Federal Land Transaction Facilitation Act and used in accordance with such Act.

Provides for the federal government and the owner of the non-federal land in a land exchange described above to equally share all costs related to the exchange, including the costs of appraisals, surveys, and any necessary environmental clearances.

Subjects the exchange of federal and non-federal lands under this section to any easements, rights-of-way, and other valid existing rights.

Expresses the intent of Congress that such land exchanges be completed within two years after the enactment of this Act.

(Sec. 6) Specifies this Act's effect with respect to the protection of the treaty rights of any Indian tribe, including the off-reservation reserved rights secured by the Treaty with the Tribes and Bands of Middle Oregon of June 25, 1855.