History and culture - Mountains
The town of Dillon was moved to make room for its reservoir
The Dillon you see today sits in a new spot because the old town was relocated in the 1960s when Denver Water built Dillon Reservoir over the original site.
Published June 10, 2026 - Last verified June 11, 2026
Dillon Reservoir is the big blue lake at the center of Summit County. Under that water sits the place where the town of Dillon used to be.
In the 1950s, Denver needed more water for its growing population. Denver Water planned a dam on the Blue River that would create a large reservoir, and the existing town of Dillon stood right where the water would rise. Over years of negotiation, Denver Water bought out the town. Buildings were moved or torn down, and even the cemetery was relocated, so nothing left behind could affect Denver’s drinking water. The dam was completed in 1963, and the reservoir filled the valley. The town reopened on higher ground nearby — its current location.
Why a newcomer might care: this explains why Dillon feels newer than its mining-era neighbors, and why the lake is owned and managed by Denver Water, a city utility based far away. That ownership shapes recreation rules on the water, such as limits on swimming and the kinds of boating allowed.
For the reservoir’s story and current rules, see Denver Water and the Town of Dillon.