The starting coordinates take you to the pincic area at the National Monument. You could have your lunch there if you remember to bring one, but it is not where the cache is. (Also you have to watch out for Yogi Bear because he loves to steal picnic baskets at National Parks!) If you solve the Adventure Lab it will give you clues to find the cache which is located outside the National Monument, within the town of Keene.
Update: The Adventure Lab at the National Monument is down right now, but the Cesar E. Chavez National Monument remains open, for those who wish to visit. If you solved the puzzle from doing the Adventure Lab previously, use those coordinates to find the bonus cache. If not, see the hint for an alternative means to find the cache, that does not require completing the AL or visiting the National Monument.
Placed with permission of the Cesar Chavez Foundation.