<P> A notable feature along the North Thompson is Little Hells Gate, a mini-replica of the much larger rapid on the Fraser downstream from the mouth of the Thompson . About 17.4 kilometres (10.8 mi) upstream from the small town of Avola, the river is forced through a narrow chute only about 30 feet (9.1 m) wide creating a rapid that resembles the Fraser's famous rapid . </P> <P> At Kamloops, the combined Thompson River river flows 15 kilometres (9.3 mi) from the confluence of the North and South Thompson Rivers before reaching Kamloops Lake, which is roughly 30 kilometres (19 mi) in length, ending at the town of Savona . From there it flows in a meandering course westwards through a broad valley area . At Ashcroft, the Thompson Canyon begins and the river turns southwestward to its confluence with the Fraser . The river is paralleled by the Trans - Canada Highway, the Canadian Pacific Railway and the Canadian National Railway . </P> <P> From Ashcroft to Lytton, the river is completely confined within Thompson Canyon, making for spectacular scenery . The Thompson River joins the Fraser River in Lytton . There is a striking stretch of dark black cliffside just downstream from Ashcroft and visible from the Logan Lake - Ashcroft highway is officially - named the Black Canyon . Just below the town of Spences Bridge was the site of a major rail disaster in the early 20th Century . Communities along this section are Bighorn, Shaw Springs, and Goldpan . </P> <P> The Thompson River valley has existed in some form for at least 50 million years; however, for much of its history, it did not drain to the southwest into the Pacific Ocean as it does today . Geologists believe water from the river flowed northward, through the Cariboo region, eventually entering what is the modern - day Peace River drainage basin and ending up in the Arctic Ocean . This flow direction is estimated to have ended approximately 2 million years ago, as the Pleistocene era of heavy glaciation began . </P>

Where does the thompson river meet the fraser river