Mining the nearshore seafloor along the U.S. West Coast could cause significant damage to commercial and recreational fisheries, marine wildlife, and the communities and tribal nations that depend on them. Industrial-scale prospecting for gold, platinum, titanium, phosphorus, and other minerals along the ocean floor is increasing worldwide. By preventing this harmful activity before it starts, the West Coast can be a model for other regions that are hoping to avoid the possible consequences of seabed mining.