Real estate magnate Don Abbey custom-built homes for himself in Montana and outside Los Angeles -- then decided to put them both on the market. His Shelter Island estate is the largest home for sale in Montana, at 24,000 square feet. It's listed at $78 million.
Read more about Abbey's two $78 million estates on the market on Yahoo! Homes' Spaces blog. And to see even more photos, go to Zillow Blog.