The prospectors' journey began for many when they climbed the mountains over the White Pass above Skagway and onward across the Canada–US border to Bennett Lake, or one of its neighboring lakes, where they built barges and floated down the Yukon River to the gold fields around Dawson City. Others disembarked at nearby Dyea, northwest of Skagway, and crossed northward on the Chilkoot Pass, an existing Tlingit trade route to reach the lakes. The Dyea route fell out of favor when larger ships began to arrive, as its harbor was too shallow for them except at high tide. Officials in Canada began requiring that each prospector entering Canada on the north side of the White Pass bring with him one ton (909 kg) of supplies, to ensure that he did not starve during the winter. This placed a large burden on the prospectors and the pack animals climbing the steep pass.