On the North Oregon Coast seaside beaches during low tide on specific dates, hunting for Razor Clams is a major recreation. They are called Razor Clams because they are shaped like the old straight razor that men used to shave - the edges of the Razor Clam are very sharp.
The traditional way in which Razor Clams are dug up is with a Shovel....the hunter stays on the water line during the low tide when the clams are accessible - to find them, they hit the sand with the handle end of their shovel...the vibration alarms the clam, which then begins to dig deeper into the sand with its large foot...and doing so, puts a dimple in the sand above it...which is observed by the hunter, who quickly digs into the sand before the clam can dig deeper.

It takes experience to master the technique....it is more of a sport than a delicacy - since the clams themselves are rather tasteless. Mostly, it is a social event for clam sportsmen who drive their cars down onto the beach at low tide and join the throng digging in the receding tide.
Originally, it was the native Indians that developed the trick of finding the buried clams.