Our History

In the 1820's mountain men began hunting and trapping the wildlife of the valleys. Later in the 1850's, emigrants traveled through the Arco area following the northern branch of the Oregon Trail, known as Goodale's Cutoff. Old cabins and barns still dot the landscape as evidence of the homesteaders who first came to the valley.

By the late 1800's, early 1900's, White Knob Mining Co. started mining ore in the Mackay area. Wayne Darlington, the superintendent of mining activity for the company was entrusted with naming the town which was the hub of activity for the enterprise. Showing loyalty to his boss and largest investor, he named the town after John W. Mackay. The town was formally incorporated in 1901.

In 1908 Arco was incorporated as a city and became the county seat when Butte County was created in 1917. Originally Arco was called "Junction" because it was a major crossroads for the state. The post office ruled out this name as there were already many other towns using the name. Rumor has it, Arco was eventually named in honor of a European Count visiting Washington DC.

As the 1900's rolled in, so did plans for a railroad and expansion of the copper mining industry along with the expansion of agriculture as pumping water became feasible. By 1918, a dam and canal system were built creating the Mackay Reservoir.

In 1949, the Atomic Energy Commission located a major complex, now called the Idaho National Laboratory, in the desert east of Arco. This lead to the birth of nuclear generated electricity which fed through power lines to Arco made it the first city in the world to be lit by atomic power. The laboratory continues today and the workers living in the area are a stabalizing factor of our current economy.