73500
In Southwestern United States like Arizona , New Mexico , and Nevada , the tree line is categorized at the point where the most extreme amounts of rainfall and temperature are sufficient for tree growth .
 Southwestern United States, Arizona, New Mexico, Nevada
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:
 Southwestern United States, Arizona, New Mexico, Nevada