Picloram (Tordon) is hereby declared to be a restricted use pesticide and the use or application of any formulation of picloram shall be prohibited in the following portion of Spokane County: An area beginning at the intersection of Brooks Road and state Highway 902; thence northerly along the Brooks Road four miles more or less to state Highway 2; thence easterly along state Highway 2 four miles more or less to the Craig Road; thence northerly on Craig Road for 1/2 mile more or less to the Airway Heights city limits; thence easterly one mile more or less along the north boundary of the Airway Heights city limits; thence southerly 1/2 mile more or less along the east boundary of the Airway Heights city limits to state Highway 2; thence easterly one mile along state Highway 2 to the Hayford Road; thence southerly three miles more or less along the Hayford Road to state Highway 902; thence westerly along state Highway 902 to the point of beginning.