Why is Hawkes opposed to the mining near his land in Montana in the novel, Man O’ War?

Hawke's ranch is adjacent to a mining operation that threatens to destroy the surrounding delicate mountain ecology. Hostilities have broken out between rancher and miner in the past; Hawkes's father, in fact, was killed by a mine disaster, and his personal loss fuels his hatred of mining and strengthens his determination to preserve his land in as natural a state as possible.