Coastal Western Hemlock Zone, which occupies almost all the land below 1,000 metres west of the Coast Mountains. It is the wettest region of Canada, with annual precipitation exceeding two metres on average and well over four metres in some places. This is in striking contrast to the drier Coastal Douglas-fir Zone from Victoria to Nanaimo (0.5 ­2m with seasonal drought). The closer you get to the mountains, the wetter it is: compare the precipitation at Vancouver City Hall of 1,255 millimetres a year with the 1,841 millimetres at Second Narrows Bridge, and the 2,720 millimetres at nearby Upper Lynn Creek. Some of Canada's largest trees grow in this zone, including giant specimens of Sitka spruce, western hemlock, Douglas-fir and redcedar. Some of these can be seen in the forests above the first 20 kilometres of the highway from Horseshoe Bay, after which there is little sign of original forest ecosystems unless you climb up the mountainsides. Farms occupy the rich alluvial soils of the Fraser Valley -- that is, where they have not been replaced by concrete or asphalt. Toward Hope, the mountains and their forests claim more land and force the highway and railways to share the narrow valley with the river.

The CPR once reigned supreme along the Fraser. The Dominion government gave the CPR a strip of land -- the "Railway Belt" -- 64 kilometres wide as part payment for the construction of Canada's first coast-to-coast railway. This land includes the entire TCH route, from Vancouver to Kamloops. The deal was quickly followed by wholesale timber extraction. After a poor start involving corrupt administrators, forest management began in earnest with fire protection and with the setting aside of numerous timber reserves. Farther east, some of these would lay the foundation for future national parks.

As you travel, note that exits from the TCH are numbered as kilometres east of Horseshoe Bay.