Lake in the Hills (often abbreviated L.I.T.H. or LITH) is a village in McHenry County, Illinois, United States. The population was 23,152 at the 2000 census. A 2006 special census put the village's population at 29,175. At the 2010 census, the population dropped slightly to 28,165.
The village is most known for its rampant residential growth which occurred most heavily in the 1990s. Once a sleepy lakeside village of cottages and small ranches, its population skyrocketed as developers flocked to the area in the 1990s. Its population increased by 17,000 people (a nearly 400% increase) over this period, making it one of the most rapidly growing suburbs of Chicago and in the United States at that time. At the height of its building boom, the village issued over 1,000 residential building permits in 1995.
In the late 1990s, the village faced the challenge of providing adequate services and infrastructure as well as establishing an identity and community unity, since many community services (Libraries, Schools, Fire Districts) were pre-delegated to neighboring communities like Huntley, Algonquin and Crystal Lake. However, the village continues to expand its resources and community offerings and is also endeavoring to diversify its tax base and provide more commercial and industrial businesses.