A Mauston man was taken into custody on a probation hold.  Police said Saturday night 18-year old Rusty Lewko had found a large black dog at Riverside Park.  He was advised by authorities to tie the dog to a fire hydrant.  A records check showed Lewko had an active warrant.  Lewko was transported to the Juneau County Jail.  The dog was taken to the Mauston PD Kennel.