55 ILCS 5/3-11009
For the purpose of enabling the county treasurer to pay in cash such warrants and other demands as may be presented to him for payment in cash, he is hereby authorized to withhold from the daily deposit of funds required of him under Section 3-11004, or to withdraw from the one or more banks, savings and loan associations, savings banks, or credit unions holding such county moneys on deposit, upon check or draft payable to his own order as county treasurer, such amounts as will enable him to maintain a petty cash fund sufficient to meet the daily demand for the purpose herein indicated: Provided, however, that the amount of said petty cash fund shall at no time exceed the sum of $5,000 in counties having fewer than 1,000,000 inhabitants or the sum of $200,000 in counties having 1,000,000 or more inhabitants. The county treasurer shall keep proper records of such petty cash fund, showing the amounts so withheld or withdrawn by him daily and the amounts paid out by him in cash from day to day. Such records shall be open to the inspection of all persons wishing to examine the same.
55 ILCS 5/3-11009