Former Indian reservations in Oklahoma
Former Indian reservations in Oklahoma are the Indian reservations in the lands that are now the state of Oklahoma. Prior to statehood, both Oklahoma Territory and Indian Territory contained suzerain Indian Nations that had legally established boundaries. The US Federal government broke up collective tribal landholdings through the allotment process before the establishment of Oklahoma as a state in 1907. Instead of reservations, Oklahoma Indian tribes have tribal jurisdictional areas, with Osage Nation being the one exception. As confirmed by the Osage Nation Reaffirmation Act of 2004, the Osage Nation retains mineral rights to their reservation, the so-called "Underground Reservation."
As a part of the process of tribal reorganization, under the 1936 Oklahoma Indian Welfare Act, the concept of “Former Indian Reservations in Oklahoma” was created; this is land identified by the Secretary of the Interior that is defined by the boundary of an Indian tribe’s former reservation in Oklahoma.
The term “Former Indian Reservations in Oklahoma” should not to be confused with the term Oklahoma Tribal Statistical Area, which is a US Census definition and represent the boundaries of reservations before Oklahoma became a state and may extend beyond the borders of the State of Oklahoma. Oklahoma Tribal Statistical information has been available since the 1990 census.
In preparation for Oklahoma’s admission to the union on an “Equal footing with the original States”  by 1907, through a series of acts, including the Oklahoma Organic Act and the Oklahoma Enabling Act, Congress unilaterally dissolved all sovereign tribal governments within the state of Oklahoma, transferred all tribal lands by Land patent (or first-title deed) to either individual tribal members, sold to non-tribal members on a first-come basis (typically by Land run), or was held in trust by the Federal government for the benefit of the members of the tribes.
By 1936, the policy of the Federal Government had changed its policy with regards to Indian tribes and Indian Nations within the state of Oklahoma were reinstated by the Oklahoma Indian Welfare Act. However, by this time, the State of Oklahoma was a Sovereign State and the powers and authorities that other non-Oklahoma reservations possess could not be taken back from the State of Oklahoma.
Congress tried to further rectify the situation through the Omnibus Budget Reconciliation Act of 1993, which authorized substantial tax incentives based on certain business activity within Indian reservations. Congress wanted to insure these benefits would also be available in Oklahoma by including in the legal definition of “Indian reservation’ the term “former Indian reservations in Oklahoma.” In a 1997 amendment, these lands were defined as those lands as the “then-current jurisdictional areas” of Oklahoma Indian tribes, as determined by the Secretary of the Interior. 
In 1998 the IRS issued Notice 98-45 which established the boundaries of the Former Indian Reservations in Oklahoma. For tax purposes, current and former lands owned by Indian tribes are treated as if they are an Indian Reservation, regardless of current ownership. Approximately 2/3 of the State of Oklahoma is treated as if it were an Indian reservation for tax purposes.  In 2010, the IRS issued Memorandum AM2010-33 which addressed a tribe in Oklahoma issuing Tribal Economic Development Bonds.
Accelerated Cost Recovery (Depreciation)
The Internal Revenue Code of 1986 (as amended) provides for additional accelerated depreciation of property (Code Sec. 168) placed on an Indian reservation (as defined above). In general, depreciation schedules are about 1/3 of the time of regular depreciation schedules. To be eligible, the property must:
- be used by the taxpayer predominantly in the active conduct of a trade or business within an Indian reservation on a regular basis
- not be used or located outside the Indian reservation on a regular basis.
- not be used in conducting or housing class I, II or III gaming as defined in the Indian Regulatory Act.
- not be residential rental property.
- not be owned by a person who is required to use the "alternative depreciation system".
- be placed in service before January 1, 2008
These accelerated depreciation schedules have been scheduled to expire, and reauthorized several times since their implementation. 
Economic Development Benefits
HUBZone A HUBZone is a Small Business Administration program that provides incentives for companies to locate and employ people in Historically Underutilized Business Zones. In additional to income criteria, any lands within the external boundaries of a Federally Recognized Indian Reservation, or a Former Indian Reservation in Oklahoma is included. Government agencies are required to spend at least 3% of their budgets with prime contractors located in HUBZones.
Department of Defense Indian Incentive
The Department of Defense (DoD) Indian Incentive Program, part of the Office of Small Business, provides a 5% rebate back to a prime contractor, based on the total amount subcontracted to an Indian-Owned Economic Enterprise or Indian Organization  To qualify, the organization must be at least 51% owned by an entity (or tribal member) of a federally recognized tribe. 
- Schlosser, Thomas P. "Tribal Civil Jurisdiction." Morisset, Schlosser, Homer, Jozwiak & McGaw. June 2001. Retrieved 12 Jan 2013.
- Sunlight Foundation. "Reaffirmation Of Certain Rights Of The Osage Tribe." Capital Worlds. 1 June 2004. Retrieved 12 Jan 2013.
- "Choctaw Nation v State of Oklahoma (Mineral Rights Arkansas River) Supreme Court 90 S.Ct. 1328 (April 27. 1970) Section I". Retrieved 2012-01-30.
- "Incentives / American Indian Land Tax Credit: Oklahoma Department of Commerce". Retrieved 2012-01-30.
- "Geographic Boundaries Determined for Tax Incentives Associated with "Former Indian Reservations in Oklahoma"". Retrieved 12 Jan 2013.
- "Tribal Economic Development Bonds Under § 7871(f) In Oklahoma". Retrieved 12 Jan 2013.
- "Figuring Depreciation Under MACRS: Recovery Periods Under GDS (Indian Reservation Property)". Retrieved 12 Jan 2013.
- "Indian Incentive Program: US Department of Defense, Office of Small Business". Retrieved 12 Jan 2013.
- "Federal Register / Vol. 74, No. 153 / Tuesday, August 11, 2009 / Notices: Indian Entities Recognized and Eligible To Receive Services From the United States Bureau of Indian Affairs". Retrieved 12 Jan 2013.