Madden planned to meet friends at Sand Bar Flat near Sonora, California on August 10, 1986 for camping and fishing. He left his family's residence at approximately 5:00 a. m. on that day and left a note for his mother explaining his plans. He brought his dog, Matilda, and his camping and fishing gear with him to the campsite. He had camped and fished at Sand Bar Flat with his father several times and was very familiar with the area. He has never been seen or heard from again. Madden's friends arrived at the designated location at Sand Bar Flat at approximately 2:00 a. m. on August 12, 1996. There was no sign of Madden or Matilda at the scene, but his gear was found near a freshly-made fire.