The Mariposa Hotel Inn is near the southern end of Mariposa, on the west side of the street between Fifth and Sixth Streets. Given that it's on Mariposa's main street and that there aren't that many streets in Mariposa to begin with, finding it should be one of your easiest missions ever. If the streetside parking is full (and even if it isn't, for that matter), there's a parking lot behind the hotel.