Tr'ondëk Hwëch'in Heritage Sites

Welcome to Tr'ondëk Hwëch'in Heritage Sites, an online resource dedicated to exploring our history and culture.

Forty Mile: Hydrology

Alaska Commercial Co. warehouses at Forty Mile during spring break-up, 23 May 1901.

Alaska Commercial Co. warehouses at Forty Mile during spring break-up, 23 May 1901.

Goetzman photographer. UAA-Bassoc Coll
May 2009 was another period of serious flood and ice damage. When a powerful wave of ice moving down the Yukon River met the open water of the Fortymile River, large ice blocks were forced onto the town site bulldozing some of the historic buildings.

May 2009 was another period of serious flood and ice damage. When a powerful wave of ice moving down the Yukon River met the open water of the Fortymile River, large ice blocks were forced onto the town site bulldozing some of the historic buildings.

Jim Regimbal photo
This aerial view shows how the small warehouse at left was shifted from its original site. The kitchen shelter to the right was originally located at the far left on the banks of the Fortymile River.

This aerial view shows how the small warehouse at left was shifted from its original site. The kitchen shelter to the right was originally located at the far left on the banks of the Fortymile River.

Jim Regimbal photo

Two major rivers affect the land under Forty Mile. The Fortymile River is one of the major tributaries of the Yukon River and is located mostly in Alaska. The silts carried down the Fortymile River created a large shallow bar at the tip of the townsite. The bar prevented large boats from docking here. The Forty Mile site was once an island but heavy silts from the Yukon River eventually filled in the channel making it part of the mainland.

During the spring break-up of the Yukon and Fortymile Rivers, Forty Mile is prone to flooding. The deposition and removal of soils by the flood waters change the shape of the site but the huge chunks of ice that crash through the town during a flood have an even greater effect. Whole buildings have been crushed and torn off the site by these icy bulldozers.

To learn more, see the story Yukon River Hydrology (PDF) from the Tr’ondëk Hwëch’in Interpretive Manual.