“What does a clue look like?" Tanith whispered.
Stephanie fought the giggle down and whispered back. "I'm looking for a footprint or something."
"Have you found one yet?"
"No. But that's probably because I haven't moved from this spot."
"Maybe we should move, pretend we know what we're doing."
They started to walk, very slowly, still looking straight down.”
― Derek Landy, Skulduggery Pleasant

The Shells

 Here are the clues to The Shells letterbox.


Use the following to help you decode the clues.


And here are some directions to the trailhead.

Getting there: From Albuquerque, take I-25 North to Bernalillo and proceed West on NM-550 for approximately 23 miles. At San Ysidro turn right and take NM-4 to the North. Las Conchas Trailhead is between mile marker 36 and 37 with a parking area on your left. From Los Alamos, proceed South on NM-4 to between mile marker 36 and 37 and the trailhead will be on your right.