60617
Petroleum exploration and extraction also takes place in the Oklahoma portion of the Ozarks , as well as in the east half of the Boston Mountains in Arkansas .
 Oklahoma, Ozarks, Boston Mountains, Arkansas
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 Oklahoma, Ozarks, Boston Mountains, Arkansas