@JLeslie Well, most of the people in Detroit don’t know what I just said. :-P
Detroit city proper was burned down in 1806 and Judge Augustus Woodward “redesigned” the street scape of the city into one that used major radial streets just like Washington, DC, extending from downtown, those being Jefferson, Gratiot, Woodward, Grand River, Michigan Ave and Fort. These roads go well into the suburbs and carve up the perfect grid pattern found outside the city limits.
However, Detroit proper also (mostly) complies with the grid system, and the entire suburban area is almost a perfect Mile Road grid system, only broken up in the lakes area in Oakland County.
Detroit is a very old city and has annexed land into its boundaries during periods of extreme growth between 1900 and 1950 (some of the quickest urban expansion ever seen). The city limits, other than the northern border at the county line (8 Mile) are completely nonsensical and supercedes the authority of the township. However, all of the township (and often incorporated city land) surrounding the city, the land that makes up most of the suburbs, is still a completely intact Township and Range system, all of which was carved up in the mid-1800s. Many suburban cities and townships are perfect 36 sq mi townships or former townships (Livonia, Warren, Canton, etc) which are the defining feature of a Township and Range system.
What you’re talking about is common out east where the geography is diverse and many places have been around since before the Northwest Ordinance created PLS. It’s called the Metes and Bounds system, where boundaries are established either arbitrarily or using a scavenger hunt style description using landmarks (30 PACES LEFT FROM ROCK ON TOP OF HILL, that sort of thing).
Detroit has sort of settled and the area that it consumes has been flush with the city for decades, so it’s difficult to see how the city ate up the county land. However, if you look at the boundaries of Ann Arbor, you’ll see that it is creeping into Washtenaw County townships which have an intact township grid, particularly the southeast side of the city (merging in with Pittsfield Township).