Sentence:  Turn off at any one of the marked picnic areas ( gasoline companies have touring service bureaus that issue booklets on national parks to <WSD>tell</WSD> you where you have barbecue facilities ) and - with soft drinks cooled from morning loading up , hamburger , buns , an array of relishes , and fresh fruit - your lunch is 75 % cheaper than at a restaurant , and 100 % more fun . 
Meaning of the word marked with <WSD> tags:  let something be known