Any governmental unit, as defined in RCW 36.93.020(1) as it now exists or is hereafter amended, may convey its real or personal property or any interest or right therein to, or contract for the use of such property by, the county or park and recreation district wherein such property is located for park or recreational purposes, by private negotiation and upon such terms and with such consideration as might be mutually agreed to by such governmental unit and the board of county commissioners or the park and recreation district board of commissioners.