A branch line to McHenry, Illinois operates during weekday rush hours in the peak direction.

Of these, 14 inbound trains originate from Harvard, three from McHenry, 13 from Crystal Lake, four from Barrington, one from Palatine, and four from Des Plaines.

Five outbound trains terminate at Des Plaines, three at Palatine, three at Barrington, 12 at Crystal Lake, three at McHenry, and 13 at Harvard.

Of these, 10 inbound trains originate from Harvard, five from Crystal Lake, one from Barrington, and one from Arlington Heights.

Metra has included the possibility of extending the McHenry branch to Johnsburg in their Cost Benefit Analysis report.

Additionally, an infill station would open in Ridgefield between Crystal Lake and Woodstock along the line to Harvard.