Kenneth C. Brugger (16 June 1918 – 25 November 1998) was an American naturalist and self-taught textile engineer.
He is noted for discovering, with his wife Catalina Trail, the location of the overwintering sites of the monarch butterfly, Danaus plexippus.
An amateur naturalist, he responded to a notice in a local newspaper written by Fred and Norah Urquhart, Canadian zoologists who were studying the migration patterns of monarch butterflies.
[2] The Urquharts had tracked the migration route as far as Texas, where it disappeared, and they thought it might continue into Mexico, so they were seeking volunteers to look for the butterflies.
[4] Eventually a dozen such sites were located and were protected by the Mexican government as ecological reserves.