78495
The eastern and central sections of the region are drained by tributaries of the Loup River and the Niobrara River , while the western section is largely composed of small interior drainage basins .
 location: Loup River; location: Niobrara River
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: Loup River, Niobrara River 
Answer:
 location: Loup River; location: Niobrara River