Bembidion can be quite abundant on the shores of bodies of water, such as along the Willamette River near Corvallis, Oregon:
Below are two videos showing me turning over some rocks on shore shown above. There are four species that are very common in that habitat: Bembidion (Plataphus) planiusculum, B. (Plataphus) vandykei, B. (“Ocydromus”) transversale, and B. (“Ocydromus”) striola. Less common are B. (Hirmoplataphus) recticolle, B. (Melomalus) planatum, B. (Plataphus) “kuprianovii”, B. (Trechonepha) iridescens, and an undescribed species of B. (Peryphus).