66389
At the turn of the 20th century , Henry Chandler Cowles was one of the founders of the emerging study of " dynamic ecology " , through his study of ecological succession at the Indiana Dunes , sand dunes at the southern end of Lake Michigan .
 Henry Chandler Cowles, Indiana Dunes, Lake Michigan
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: media, plant, vehicle, astronomical object, time, disease, animal, location, person, organization, mythical figure, food, biology, geographical phenomenon, instrument, event 
Text: {0} 
Answer:
 Henry Chandler Cowles, Indiana Dunes, Lake Michigan