During the silver rushes of Idaho during the 1870s and 1880s, towns and mine operations required a substantial amount of water to feed boilers and to wash the gravels for paydirt. In the early 1880s, Chinese workers were paid to build a ditch from a high mountain lake just across the border into Montana, and to connect to mining operations in Murray, Idaho. Chinese crews excavated the fifteen mile ditch to a depth of six to seven feet in some places, and even constructed rockwork to add extra support. However, just as the crews finished their work a rival mining company used explosives to destroy the dam at the lake, and the ditch was never used again. The site is now located on the Thompson Divide on the Lolo National Forest.

Portion of the Thompson Pass China Ditch