86384
Most of the largest fields are in the lower parts of the foothills to the mountains on either side of the valley , including monstrous reservoirs such as the Kern River and Midway-Sunset fields ; in the bottomlands , the fields are more deeply buried and harder to find , as they have no surface geological expression , such as a line of hills indicating an anticlinal structure hiding an oil reservoir .
 location: Kern
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: location, person, organization 
Text: {0} 
 Entities: Kern 
Answer:
 location: Kern