72220
Public activities As owner of the Diamond Cross Ranch , an parcel along Montana ’s Tongue River and on the northern end of the Powder River Basin , Mars has been active in opposing the development of his part of what 's been called the " most productive coal and natural gas fields in the nation . "
 Montana, Mars
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 Montana, Mars