270878
Rancho Potrero de San Carlos was a Mexican land grant in present day Monterey County , California given in 1837 by Governor Juan B. Alvarado to Fructuoso del Real , an Indian .
 Monterey County , California, Juan B. Alvarado
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 Monterey County , California, Juan B. Alvarado