The Irish Hills: glacial lakes, an old road, and a fast track

Northwest Lenawee County rises into the Irish Hills because two old ice lobes met here. Michigan State University describes the area as an interlobate moraine near the former junction of the Erie and Saginaw lobes. The glaciers left ridges, hollows, and kettle lakes behind. That is the sturdier explanation for the landscape; the familiar story that Irish settlers simply thought the hills looked like home is local lore, not the fact this page needs to lean on.

U.S. 12 carries the human history through those hills. At Cambridge Junction, the road follows the old Chicago Road and an earlier Old Sauk trail between Detroit and Chicago. Walker Tavern has watched that route since about 1832. Farther into the lake country, W.J. Hayes State Park provides public access and a designated swimming area on Wamplers Lake and Round Lake.

Then the landscape changes character again. Michigan International Speedway occupies more than 1,400 acres in Cambridge Township. Its first race was in October 1968, and its first NASCAR race followed in June 1969. The two-mile D-shaped oval has long straights and 18-degree turns. In a 2025 analysis, NASCAR put its Next Gen average pole speed at 192.04 mph, fastest among tracks on that year’s schedule. That is strong evidence for the speed story, but it is a dated comparison, not an all-time promise.

The track now promotes one annual summer NASCAR weekend, while its wider calendar includes driving experiences and non-racing events. Dates and event names change, so use the current MIS schedule before planning around race traffic or camping. The old “fastest place twice a summer” line no longer matches the calendar.