Final answer:
The state that borders the Pacific Ocean and contains Coos Bay is Oregon, known for its significant role in westward expansion and settlement in the United States.
Step-by-step explanation:
The state that has the Pacific Ocean and Coos Bay within its borders is Oregon. Coos Bay is a notable geographic feature situated along the Pacific Coast, which is part of the larger Pacific Northwest region. This region is renowned for its distinct climate, economy, and as a part of the Ring of Fire that encircles the Pacific Ocean.
Oregon's prominence during the period of westward expansion in the United States contributed significantly to its development and settlement, leading to the 'Oregon Fever' which saw thousands of American settlers travel westward via the Oregon Trail. Furthermore, Oregon's history includes a rich tapestry of territorial claims that were eventually resolved, establishing Oregon's place in U.S. geography firmly along the Pacific Coast.