text: The flotation plant was built in 1923 to process the "fines", which were less than 0.3 cm in size.These fines were mixed with water, oil, and buffering chemicals, before air was bubbled through the solution. Copper ore attached to the air bubbles, and floated to the top, where it was skimmed off, dried and sacked. Tourism
  In the 1980s, Kennecott became a popular tourist destination, as people came to see the old mines and buildings. However, the town of Kennecott was never repopulated. Residents involved in the tourism industry often lived in nearby McCarthy or on private land in the surrounding area. The area was designated a National Historic Landmark in 1986 and the National Park Service acquired much of the land within the Kennecott Mill Town in 1998. Popular tourist activities while visiting Kennecott include glacier hiking, ice climbing, and touring the abandoned mill. Visitors may also hike to the abandoned Bonanza, Jumbo and Erie mines, all of which are strenuous full-day hikes, with Erie Mine being a somewhat terrifying scramble along cliffs overlooking the Stairway Icefall. Local guide services offer all of these hikes if one would like some route-finding assistance. 