Coal mining declined as an industry from the 1930s through 1950s as natural gas replaced coal. The Black Diamond mine closed in 1956, and Lafayette became once more an agriculture-based community. As Denver and Boulder grew, residential growth in Lafayette increased. With the increase in residential growth, the farm-based economy changed and commercial, small industrial and manufacturing factors became more important. Lafayette's ethnic diversity continued to expand with population growth. In 1940, 76 Hispanic or Latino adults were recorded as residing in Lafayette, with a total population of 2,062. By 2016, 4,400 (18 percent) of Lafayette's 25,000 residents were Hispanic or Latino.