Revenue from the fees authorized by this chapter shall be deposited in the Big Game Management Account established in Section 3953 and, upon appropriation by the Legislature, shall be expended as set forth in that section. Administrative overhead shall be limited to the reasonable costs associated with the direct administration of the program. These funds shall be used to augment, and not to replace, moneys appropriated from existing funds available to the department for the preservation, restoration, utilization, and management of bighorn sheep. The department shall maintain internal accountability necessary to ensure that all restrictions on the expenditure of these funds are met.