Crystal Lake is a city in McHenry County in the U.S. state of Illinois. Named after a lake southwest of the city's downtown, Crystal Lake is 45 miles northwest of Chicago. The population is 40,269 as of the 2020 Census, a 1.2% decrease from 2010. Crystal Lake is the largest city in McHenry County, part of the Chicago metropolitan area. History Founding The City of Crystal Lake traces its origin to two separate communities which were established in the 1800s. Those communities were generally known as Nunda and Crystal Lake. In 1835, Ziba S. Beardsley had come to the shores of the lake and commented that the "waters were as clear as crystal", thereby giving the lake its name. Ziba Beardsley continued south to Naperville. In February 1836, the first white settlers, Beman and Polly Crandall and six of their ten children, came from New York State traveling to Crystal Lake in a covered wagon. Their original cabin was built in the vicinity of today's intersection of Virginia Street and Van Buren Street. Four of the Crandall children were born there. Najah Beardsley's family was the second to settle in the area; his grandson, William Beardsley, was the first white child born on the Crystal Lake prairie, on May 7, 1837. The town was first known as Crystal Ville. It was changed to Crystal Lake sometime before 1840. The area known today as downtown Crystal Lake was first called Dearborn and later, Nunda (pronounced locally as “Nun-day”), from an area in New York where many settlers originated. The village of Dearborn was founded in the 1850s after an extension of railroads through the area. The first train station was built in 1856, although it was pre-fabricated and shipped from Chicago on a flatcar. At that time, the main business district for the village of Crystal Lake was located on Virginia Street, about one mile (1.6 km) southwest of the railroad station. The railroad served to connect both the people and industries of Crystal Lake and Dearborn to Chicago and the rest of the country. Dearborn grew quickly due to this new rail connection. On October 7, 1868, Dearborn's name was changed to Nunda. The village was platted in 1868 by local surveyor, John Brink, after whom a downtown street is now named. The village included the area now generally bounded by Illinois Route 176 on the north, Crystal Lake Avenue