"The Great Colorado Payback is responsible for reuniting Coloradans with their lost or forgotten assets.

For example: if you have lost track of a bank account, stock certificate, or a retirement account; misplaced a rebate check, reimbursement or paycheck from a business; or moved prior to receiving your Colorado state tax rebate, the bank, business or state agency is required by law to file a report and forward those assets to the Unclaimed Property office of the Colorado State Treasurer.

Even businesses lose track of property and payments, occasionally resulting in unclaimed property which can be claimed. Corporations, schools, hospitals, and small businesses are also listed among the many individuals whose assets are in the possession of the State.." (taken from Colorado State Treasury Website)