So [Robert Gray in 1792] gave the United States a claim recognized by the polity of nations. Discovery and entrance of a river mouth gave the discovering nation sovereignty over the valley and watershed of the river and over the adjacent coast. The two empires that were pushing westward in the interior toward this same perimeter had met on the Pacific shore. Inland Great Britain was far in the lead – but the Americans had reached Oregon [Columbia River] first. . . .
In September, after sailing round his island, Vancouver was back at Nootka, where Gray had meanwhile put in after a profitable trip up the coast. The Spanish commandant, Bodega y Cuadra, told Vancouver that Gray had found a river at Deception Bay after all and gave him a copy of Gray’s chart. He sailed south to investigate, though sure that the Yankee could have found only a small river at best. The Columbia confirmed him a little in that the water at the bar which caused the breakers was not as deep as it had been in the spring flood. He sent Lieutenant Broughton in the brig Chatham over the bar on October 19 1792 but found no channel he thought it safe to take the Discovery into and two days later sailed for California. Broughton found that it could not be called a small river and decided that Gray had not entered it. Gray’s chart showed that he had gone thirty-six miles upstream. By triangulation, computation, and divination Broughton scaled this down to fifteen miles and decided that up to here the river had not narrowed enough to be called anything but a sound. A fresh-water sound that opened on the ocean would be unusually interesting geography but it would do to peg down an imperial claim. Broughton anchored in what he took to be one of Gray’s anchorages and went on by small boat to a total of a hundred miles above the bar, almost to the mountains an~ with the river shoaling to three fathoms. That ought to do it and the names he gave to peaks and other landmarks ought t stick. He claimed for Great Britain the river Gray had named all its watershed, and the adjacent coast. Vancouver accepted his findings, “having every reason to believe that the subjects of no other civilized nation or state had ever entered this river before.” So did British diplomacy down to 1846. Two expanding empires had now made claim to the Columbia River and the unknown area it drained. For both of them the immediate value was the trade in sea otter furs, the maritime Northwest trade.
[Lewis and Clark] left various rosters and announcements in the hands of various Indians to be shown to traders when they should appear. They carved and branded trees and affixed notices to …J them, recounting their achievement. (No one said so but in ;- the polity of nations this was ritual to buttress the claim which the United States had to the Columbia drainage through Robert Gray’s discovery. The ritual announced that they had traversed the country and had occupied it.) Then in some of the dugouts they had made at the Clearwater and two of the much better seafaring canoes of the Columbia River tribes, they abandoned Fort Clatsop on March 23 1806.