Placer gold was discovered in Eureka in 1860 by Charles Baker, but mining activities were halted due to a treaty with the Ute Indians in 1861. When more gold was discovered near Silverton in 1873, miners returned to the area under the terms of the Brunot Treaty, which gave them access to the land. As the town grew it established its own post office in 1875 and many other businesses formed and was later connected to the Denver and Rio Grande Railroad via the Silverton Northern Railroad in 1876. Eureka never had a large population, but it did have a couple hundred miners in the town. The area mines and mills exchanged hands numerous times to varying degrees of profitability, however due to lack of ore reserves and the railroad removing the railway, the town suffered greatly. The town managed to hang on until 1978 when the working mining tunnels collapsed and were flooded by the above ground lake. All that remains are the remains of the mill and a restored jail.