Old Lexington Gardens is in the heart of the largest historic district of the United States. Old Lexington Gardens is the site of many of Butte's firsts. It has Butte's first stamp mill (an ore crushing machine from 1867). It is the site of Butte's first smelter, first high school, and one of Butte's first patented mine claims. Eventually, a total of 512 total mines would be claimed in Butte. The sale of this land was part of a deal that made Montana's first millionaire. The gardens also has a full scale re-creation of a floral butterfly that was in Butte from 1899 to 1973 along with extensive historic interpretive signage that tells a general history of Butte.

Butte, once the largest city in the Rocky Mountains, and has been called the "Richest Hill on Earth" due to the mining operations of gold, silver, and copper. Montana Resources' Continental Mine produces copper, molybdenum, and some silver. They generally mill around 47,000 tons of ore per day.

The Butte mining district encompasses an area of approximately 2 by 4 miles which has produced huge commercial quantities of not only copper (21.5 billion pounds) but also significant amounts silver, gold, manganese, zinc, lead and molybdenum. FYI The United States holds the largest stockpile of gold reserves in the world by a considerable margin. In fact, the U.S. government has almost as many reserves as the next three largest gold-holding countries combined (Germany, Italy, and France).