Traditionally, transportation was primarily by dog sleds (land) and kayaks (water). Sea mammal hunting and fishing in the Bering Sea region took place from both small narrow closed skin-covered boats called "kayaks" and larger broad open skin-covered boats called "umiaks". Kayaks were used more frequently than umiaks. Traditionally, kayaking and umiaking served as water transportation and sea hunting. Dog sleds are ideal land transportation. Pedestrian transportation is on foot in summer and snowshoes in winter. Only small local road systems exist in Southwest Alaska. Only a few closely adjacent villages are linked by roads. Today, snowmobile or snowmachine travel is a critical component of winter transport; an ice road for highway vehicles is used along portions of the Kuskokwim River.