Final answer:
The Columbia River flows from Columbia Lake into the Pacific Ocean and has the tributary Snake River. It is the largest river in the Pacific Northwest region and originates in Canada.
Step-by-step explanation:
The river that flows from Columbia Lake into the Pacific and has the tributary Snake River is the Columbia River. The Columbia River is the largest in the Pacific Northwest region of North America and one of the largest rivers in North America. It originates from Columbia Lake in British Columbia, Canada, and flows through the states of Washington and Oregon, eventually emptying into the Pacific Ocean.