It is well documented that Robert Gray sailed into the estuary of the Columbia River, and thus discovered it, 1792 and that 17 years earlier, in 1792, Bruno Heceta described the mouth of the river and, while unable to enter it, named its northern and southern capes. But these explorers were not the first to leave a written record of their voyages and discoveries along the Pacific coast. The first record, although not specifically about the Columbia, was much earlier.
In the year 458, a Chinese monk named Hwui Shan, accompanied by four other monks, sailed north to Japan and the Kamchatka Peninsula, east to the Aleutians and present-day Alaska, and then south along the Pacific coast, a region called Fu-Sang in Hwui Shan’s narrative of the voyage. Fu-Sang apparently encompassed the entire Pacific Coast from Alaska to Baja California. Hwui Shan’s descriptions of native peoples and their customs are detailed and accurate, based on what modern historians know about those ancient cultures. The journey is recorded in official documents of the Sung dynasty for the year 499,when the monks returned to China. They apparently reached Fu-Sang at about the time of the fall of the Western Roman Empire, 476 AD, stayed for a period of years and then returned to China.
The accuracy of this story has long been hotly debated, for Hwui Shan also wrote about the weird “Kingdom of Women” the monks encountered, whose inhabitants were half human and breastless. But exaggeration was common in early accounts of western exploration. Twelve centuries after Hwui Shan, Spaniards searched what is now northern Mexico and the American Southwest for the Seven Cities of Gold and a race of three-breasted women.
Modern historians generally accept the Chinese account as authentic. The larger debate is over the significance of the voyage. The five monks did not claim Fu-Sang for their emperor, as their expedition was not one of conquest. Their intent apparently was only to observe and learn. And as such, their visit is little more than a historical footnote, a curiosity. But assuming it is true, and it seems plausible enough, then the first recorded exploration to pass the mouth of the Columbia River was the voyage of Hwui Shan, more than 1,300 years before the arrival of European explorers.