The William Ingersoll Estate is a former summer home complex on an island in Sand Point Lake in the U.S. state of Minnesota, in what is now Voyageurs National Park.

He purchased the island property in 1927, when the Boundary Waters region had become a wilderness vacation destination for adventurous upper-class Midwesterners.

[2] The main cabin collapsed in 2014 and was subsequently removed by the National Park Service, with the hope of reconstructing it if funding ever became available.

The second is another prefabricated cabin with six rooms, built for Ingersoll's friend and frequent guest Robert B. Chiperfield, a long-serving congressman from Canton.

The sixth contributing property is the cultural landscape itself, which comprises garden beds, stone paths, fencing, a bird house, and the careful siting of the buildings to maximize lake views and maintain privacy.