A landmark event occurred in 1928 when the Mond Nickel Company merged with the International Nickel Company to form INCO Ltd. This merger was the result of the two companies being unable to agree on the development of mining operations in the Frood area of Sudbury. At that time, the ore-body was spread across the properties of both companies and rather than setting up independent mining operations (which would have resulted in costly duplication), they decided to merge. In the past, the Mond Nickel Company and the International Nickel Company were friendly rivals who controlled the majority of the world's nickel market, but together, INCO Limited would become the largest mining company in the world.

Although the merger was beneficial to the mining conglomerates, the people of Coniston could not help but feel pessimistic about the future. Prior to the merger, the Mond Nickel Company had intended to establish Coniston as its Canadian headquarters. However, when INCO Limited was formed, these plans were abandoned and Copper Cliff became the Canadian headquarters for the company.

When the Depression struck in 1929, Coniston residents felt the impact. A large number of workers were laid off from the smelter because of a reduction in output and only a small portion of these individuals were offered work at the Copper Cliff smelter (and even then it was only for two or three days a week). By 1933, things began to turn around for the community. Nickel production was on the rise and Coniston's smelter was beginning to increase production and rehire its workers.

• The Town of Coniston