Salish aboriginal legends indicate that there has been a large sea creature living in south central British Columbia's Lake Okanagan long before the arrival of the white man. According to folklore, the lake monster was originally a demon possessed man who murdered a local man named Old Kan-He-K (who lent his name to Lake Okanagan). As punishment for the homicide, the gods turned the murderer into a sea serpent who would be stuck at the scene of the crime for all of eternity. Out of fear that the creature, known as N'ha-a-itk, would rise out of the waters and claim their lives, the Salish Indians would never canoe near the area of his lair without first carefully scanning the water and bringing an offering of small animals to appease the monster. According to the legend, the lake monster's lair is a cave at the bottom of Lake Okanagan, under Squally Point and near Rattlesnake Island.

The first documented sighting of the creature occurred in 1872 by a Mrs. John Allison and the sightings have continued into the present. Some of the sightings are remarkable because of the quantity of people who saw the monster at the same time. On September 16, 1926 for instance, thirty car loads of people all witnessed the monster emerge from the lake, just off of Mission Beach. It is not surprising, in that case, that there are commonalities to the sightings. Most of the accounts describe a green serpent about two feet in diameter with the head of a horse or a goat. The length of the sea creature generally varies from 15 feet to 50 feet.

Although most sightings of Ogopogo are met with amusement and skepticism, the depth of Lake Okanagan does make the existence of such a creature somewhat plausible. The lake is 169 kilometres in length, extending from Vernon at the north to Penticton in the south with Kelowna in the middle, with depths of almost 1,000 feet in some parts. Despite the fact that there is little documented proof that the creature exists, apart from multiple eye witness accounts and grainy photographs and video tape, some scientists believe that Ogopogo may be a giant serpent or an aquatic dinosaur. Some scientist have even gone as far as to identify the sea creature as basilosaurus cetoides, a primitive form of whale.

It may be disputable as to whether Ogopogo is an urban legend or actually exists, but one thing is clear - he certainly is good for the Okanagan tourism industry.