This SPECTACULAR estate, dubbed Whispering Rock, is located on the 24-acre Shelter Island of Montana’s Flathead Lake. There is a 24,000 square foot main house and a 4,500 square foot guest house. The entire estate encompasses over 50,000 square feet. The exterior is made of Indiana Limestone and the interior millwork features African-sawn Mahogany, Italian Marble and Portuguese Limestone. It was listed for $105,000,000 back in September of last year, but is now on the market for $78,000,000. It is owned by Donald G. Abbey, who just put his 47,000 square mega mansion in Bradbury, CA on the market for $78,800,000.