Homestake Hydroelectric Plant No. 1

To avoid buying coal, the Homestake Gold Mine paid for a 5-mile, 8-tunnel water diversion through solid canyon rock — engineered so precisely that crews boring from opposite ends met with no measurable error — and the plant it powered still generates electricity over a century later.

📍 Spearfish, SD 📅 1912–Present 🏛️ Power Plant ⚖️ Still Here

The Story

Seeking to replace expensive coal-fired steam power at its Lead mine, Homestake self-funded Hydro Plant No. 1 around 1910 with its own capital. A diversion dam up-canyon at Maurice sent water roughly 5 miles through eight tunnels cut through solid rock, dropping about 800 feet to the plant's turbines. It started up April 12, 1912, transmitting power to Lead in an early example of long-distance AC transmission. The City of Spearfish bought the system in 2004 to protect streamflow, and it still generates power today.

Surprising Facts

→ Homestake paid for the whole project with its own capital — no bank financing.

→ Tunnel crews boring 5 miles from both ends met with no significant misalignment.

→ It has generated power continuously since 1912, and the city now offers public tours.

Frequently Asked Questions

Where is Homestake Hydroelectric Plant No. 1?
Homestake Hydroelectric Plant No. 1 is at S Canyon St (mouth of Spearfish Canyon), Spearfish, SD. Explore it on the When It Was interactive map.
How old is Homestake Hydroelectric Plant No. 1?
Homestake Hydroelectric Plant No. 1 dates to 1912, making it more than 114 years old.
Can you still visit Homestake Hydroelectric Plant No. 1?
Yes — the site at S Canyon St (mouth of Spearfish Canyon), Spearfish, SD still stands and remains in use today.

More Black Hills History

Sources

https://www.spearfishhistory.org/2016/04/the-two-spearfish-canyon-hydro-plants_18.html