It's all a matter of time. And water.

Mountains; all massive, jagged rocks:

Tall, sharp peaks, to our south, in Washington State.

Mount Baker

Which will eventually crumble to this:

Beach rocks, with barnacles and brown rockweed. Boundary Bay.

And then be ground down and smoothed out, by water and critters, to this:

Sand, still being ground down, this time by worms and snails. And water. (Other tracks; human, dog, sandpiper.)

Just give it time.