In 1902 the Val Verde smelter burnt to the ground. A new company was formed, the Consolidated Arizona Smelting Company, which built a giant smelting plant upon the ashes of the Val Verde works. This operation served not only local mines, but operations throughout the then Arizona Territory. The Val Verde post office was renamed Humboldt in 1905 to honor Baron Alexander von Humboldt, who had visited New Spain early in the 19th century and predicted that greater riches would be found to the north (interpreted by early twentieth century promoters as the Bradshaw Mountains region). Around this time the town of Humboldt began to develop. The smelter and the railroads into the Bradshaws created probably the most widespread mining boom in the county. By 1907 the population had reached 1,000. With two daily trains, business in the town boomed and the city decided to showcase their development by hosting a Labor Day celebration that year. The celebration featuring a parade on Main Street became an annual tradition, now organized by the Agua Fria Chamber of Commerce and held on the last Saturday in September.