Millions of years ago, the Columbia River cut through the Cascade Mountains and formed a deep gorge more than 80 miles long. Native Americans built large communities along its shores and it became a busy center for trade. With an estimated 20 million salmon passing over its falls each year, the Columbia River Gorge became one of the greatest fishing sites in North America. The Native Americans, who relied on the salmon for their survival, built large platforms over the rapids to catch the fish with spears and nets. The river’s location made the area important for westward expansion. Lewis and Clark discovered the Columbia River was the “gateway to the Pacific” in 1805. The gorge was also a resting point on the Oregon Trail, and many weary pioneers settled in the region. Eventually, steamships and railroads made travel along the Columbia River Gorge safe and convenient. Today, the gorge forms the border between the states of Washington and Oregon, and is federally protected. The Columbia River Gorge is a popular destination for hiking, sight-seeing, biking, and water sports. One of its most memorable sites is the Vista House, which is located on a cliff 733 feet above the river. The observatory provides visitors with spectacular views of the gorge.