Simplify the following text for a Grade 11 native English-speaking person.
Original: The main source of revenue comes from Coffee that is grown in the mountainous regions of the province , and during the coffee harvest , there may be roadblocks , where soldiers ensure that the coffee is delivered to the government and not the black market .
Simplified: Coffee is grown in the mountainous regions of the province , and during the coffee harvest , there may be road blocks , where soldiers ensure that the coffee is delivered to the government and not the black market .