The Suburbs Keep Pushing West. Is Marengo Next?

Draw a line down the middle of McHenry County. On the east side: Wonder Lake, up 50% since 2020. Huntley, adding nearly a thousand residents a year. Crystal Lake, the county's largest city, growing steadily to 42,000. On the west side: Harvard, losing population despite having a Metra station and an industrial park. Marengo, growing so slowly it adds about one new household every two weeks. ¹

The pattern is geographic, not random. The eastern half of McHenry County sits within commuting range of Schaumburg, Arlington Heights, and the Lake County job corridor. Route 14, Route 12, and Metra's Union Pacific Northwest line connect those communities to employers. According to Census Bureau commuting data, McHenry County's median one-way commute is 34 minutes, among the longest in the Chicago metro area. ⁵ For residents on the eastern side, that 34 minutes reaches suburban office parks. For residents in Marengo or Harvard, the same drive barely reaches Woodstock.

McHenry County added 2,201 residents last year, bringing it to 317,751, according to the Census Bureau's 2025 population estimates. ² That is a 0.6% increase, modest but real, and the strongest annual gain since before the pandemic. The county has added nearly 8,000 people since the 2020 census. But as the map shows, that growth is not landing evenly.

The starkest contrast is between Wonder Lake and Harvard, separated by about 20 miles. Wonder Lake sits along Route 120, connected to the eastern suburban corridor. Census estimates show it has grown from 3,970 to nearly 6,000 residents since 2020, a 5.9% annual rate. ¹ Harvard, the county's westernmost city, sits on Route 14 near the Wisconsin border. It has a Metra station, a 303-acre former Motorola campus that has sat empty for nearly two decades, and a downtown with century-old storefronts. ⁷ Yet it is losing population at 0.13% per year. ¹ The Metra station and industrial land have not been enough to overcome Harvard's distance from the employment centers driving eastern growth.

Annual population growth rate by municipality, 2020-2025

Declining Flat Growing Boom

Marengo Major routes

Source: U.S. Census Bureau Population Estimates 2025 · McHenry County GIS

Why hasn't transit access converted into growth for Harvard? Part of the answer is that commuter rail connects to downtown Chicago, not to the suburban job centers where McHenry County residents actually work. Census commuting data shows that fewer than 15% of McHenry County workers commute to Cook County. ⁵ The jobs are in the collar counties, and the roads to those jobs favor the eastern side.

Marengo is between these two trajectories. The city's population is 7,772, up from 7,552 in 2020, according to Census Bureau estimates. ³ That is 37 new residents per year, a 0.48% growth rate. It is enough to sustain the tax base but not enough to expand it. Building permit revenue in the current budget fell 60% as the MI Homes subdivision neared completion, dropping from $249,000 to a projected $100,000. ⁴ The next wave of residential development is not yet in the pipeline.

The growth pattern resembles earlier waves of Chicago-area suburban expansion. Naperville grew from 42,000 to 128,000 between 1980 and 2000 as the I-88 corridor brought western DuPage County within commuting range. Plainfield followed in the 2000s. But the comparison has limits. Those communities had expressway access, proximity to established employment centers, and municipal water and sewer systems ready to scale. Western McHenry County has none of those advantages today. Route 23 is a two-lane state highway, not an interstate, and Marengo's water and sewer system is in the middle of a multimillion-dollar repair cycle. ⁴

U.S. Census Bureau estimates, 2020-2025

This is not a crisis. McHenry County is prosperous: unemployment is below the state average and household income is above it, according to the McHenry County Economic Development Corporation. ⁶ But the growth pattern has implications for every western community's fiscal planning. Property tax revenue, sales tax collections, and development fees all follow population. When growth concentrates on one side of the county, the other side has to hold services steady on a tax base that is barely growing.

For Marengo, the question is not whether Chicago's suburbs will eventually reach this far west. The question is what has to change first. The Route 23 corridor, sewer and water capacity, zoning that permits denser development, and employers willing to locate beyond the current suburban edge are all preconditions, not certainties. Growth is not something that arrives. It is something a community has to be ready to absorb.