Thompson River
The Thompson River is the largest tributary of the Fraser River[1] in the south-central portion of British Columbia, Canada. The Thompson River has two main branches called the South Thompson and the North Thompson. The river was named by Fraser River explorer, Simon Fraser, in honour of his friend, Columbia Basin explorer David Thompson.
Geography
The South Thompson originates at the outlet of Little Shuswap Lake and flows approximately southwest for 55 kilometres (34 mi) through a wide valley to Kamloops where it joins the North Thompson. Highway 1, the Trans-Canada Highway and the mainline of the Canadian Pacific Railway parallel the river. The major rivers flowing into Shuswap Lake are the Shuswap River from the south, via Mara Lake and Sicamous Narrows, the Seymour River flowing into Seymour Arm the easterly of the two northern arms of the lake, the Salmon River flowing into Salmon Arm, the easterly of the two southern arms, at the town of Salmon Arm, and the Adams River which enters the lake from the north near its outlet into the Little River, which runs 5 km to Little Shuswap Lake and is in effect the South Thompson River in all but name.
The North Thompson originates in the mountains west of the community of Valemount and flows generally south towards Kamloops and the confluence with the South Thompson. For most of its length, the river is paralleled by Highway 5, and the Canadian National Railway. The North Thompson valley provides the primary connection from the southern parts of the province with the Yellowhead Pass, the lowest pass through the Rocky Mountains. The major tributary is the Clearwater River which joins the North Thompson at Clearwater. Most of the Clearwater drainage is protected by Wells Gray Provincial Park.
At Kamloops, the combined Thompson River river flows 15km from the confluence of the North and South Thompson Rivers before reaching Kamloops Lake, which is roughly 30km in length, ending at the town of Savona, just above the confluence of the Deadman River, and from there flows in a meandering course westwards through a broad valley area, notable as the location of Walhachin and the Semlin Ranch. At Ashcroft, beginning just above the confluence of the Bonaparte River at that town, 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.
From Ashcroft to Lytton, the river is completely confined to the Thompson Canyon, making for spectacular scenery. The Thompson River then joins the Fraser River in Lytton where it flows down the Fraser River Canyon and eventually into the Pacific Ocean. 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, the site of a major rail disaster in the early 20th Century. The Nicola River joining from the south at Spences Bridge. Communities along this section are Bighorn, Shaw Springs, and Goldpan.