If I were a fan when Warner was first publishing the series I think I would have been disappointed with this ending. The mystery is OK, some parts are pretty easy to guess, but some of the mystery is pretty subtle. But there's no resolution with the characters. It's just like any other Boxcar Childr...
The mystery was so obvious to me that I kept wondering why everyone was confused for ~90% of the book. I remember Benny Uncovers a Mystery (#19) being a lot more mysterious when I was a kid though, so the intended audience of the Boxcar Children novels might enjoy this one.
I mixed this book with the one where they go to camp(?) and learn about the ocean. Also I thought Benny hurt his foot on the beach as a catalyst to... something. But that might have been a scene from another book I read in the 90s (Baby-Sitters Club?). Something that does bother me about the Boxca...
I wish this one were longer! The ending wraps everything up so quickly, there's so little time to process the end of the story. Still I enjoyed this one a lot.
Would have been better without the vague, hand-wave-y "Indian" references. I liked Lovan and David as characters but was not a fan of the lack of specificity regarding their Indian tribe/customs/language/etc.