The Sandy River Delta, more than 1,000 acres on the eastern side of the Sandy River, is now public land and part of the Columbia River Gorge National Scenic Area.
The first record of it by English explorers was in 1792 when Lt. William Broughton sailed up the Columbia River on a 'scouting' party for Captain George Vancouver. The British lost the race to claim the Columbia to an American fur trader, Captain Robert Gray, who beat them into the mouth of the river, but they made a go of it anyway. Broughton sailed to the delta naming Mt. Hood after a British admiral and taking possession in the name of the king. Flag Island in the Columbia honors that expedition.
Lewis and Clark explored the area on November 3, 1805, commenting on the large amount of sand flowing from the Sandy, which they named the Quicksand River. The following spring they were back, camping and hunting in the area for many days and finding seals in the mouth of the Washougal River, on the Washington shore opposite Troutdale. (May 2001 Champion)