The Lower Mainland

About one million years ago, massive continental ice sheets covered what is now the lower mainland. The ice moved under its own weight, pushing rock debris such as silt and gravel into the Pacific ocean. Icebergs frequently calved away at the seashore, volcanoes erupted inland and global climates fluctuated, causing the thickness of the ice sheets to vary. At times, they were as thick as 1,500 metres--enough to bury all but the highest peaks of the Coast Mountains. The last major Ice Age started coming to an end about 14,000 years ago and the ice sheets began to melt. When the toe of the ice sheet retreated from the area it left a vast depression still sunken from the weight of the ice and this entire area known as the Lower Mainland was covered in salt water. Isostatic rebound started to occur about 10,000 years ago and by about 5,000 years ago enough land had emerged to push the eastern coast of the Georgia Strait as far west as present-day New Westminster. It was then that the Fraser River began to build a stable delta many metres thick and which, still today, grows up to 3 metres every year.

“The Fraser River is the largest river in British Columbia draining a watershed of approximately 233,000 square km and extending nearly 1278 km in length. The river is a recreational amenity to many....”

"Thursday 9th [August, 1827]. The Fire which had raged with so much violence Yesterday, broke out again today with redoubled fury on the setting in of the Breeze from Sea. “

“The earliest maps clearly show Brae and McMillan islands separated by a channel, and the upstream end of McMillan Island located about 750 meters upstream of its present location. “

Fraser River

Houston Trail - the Uplands

Brae Island / Bedford Channel