Okla. Stat. tit. 62, § 62-120.4: Property accounts

The property accounts set up, maintained and kept as provided by

law, for tangible property and equipment, other than expendable

supplies, shall be maintained on cost basis, representative of

capital values of invested state monies, and never charged with

appreciation nor credited with depreciation; but on sale or exchange

and reacquisition of properties of comparable function as

hereinbefore provided, the capital account thereof shall be credited

with the first or capital cost of the item disposed of and charged

with the gross cost of the substitute item acquired; unless and

until the Legislature shall require that the depleted or depreciated

value shall be charged to expense.