Los Mochis is a port city on the eastern coast of the Sea of Cortez. It's main interest for tourists is as a transportation hub. Los Mochis has an airport, ferry docks for transport across the Sea of Cortez to Baja California. It is best known as one of the two terminus points for the Chihuahua al Pacifico Railroad (El Chepe) --- the magnificent train ride through the rugged Copper Canyon.
Los Mochis has a small airport (IATA:LMM) serving a limited range of destinations. Most flights are on small regional jets or turboprops. Direct flights to Los Mochis are available from:
Delta has apparently stopped its flight from Los Mochis to LAX.
The Chihuahua al Pacifico Railway is one of the world's most spectacular train trips. The trip between Los Mochis and Chihuahua is about 14 hours each way. First class trains leave each end point at 6am and the second class train leaves one hour later. 
Ferry boats run between La Paz and the Topolobampo docks. The ferry transports both passengers and vehicles, though there has been talk in recent years of restricting RVs. Since privatization fares are increasing very rapidly, about $80USD currently (salon class).