Chicago, Illinois

Schaumburg	Kenosha, Wisconsin	Holland, Michigan
Aurora	Chicago	South Bend, Indiana
Champaign/Urbana	Danville	Lafayette, Indiana
Today's location: not yet announced

The Chicago, IL graticule is located at latitude 41, longitude -87. It includes almost the entire city proper (excluding the area north of Devon Ave), the south suburbs, Kankakee, Gary and NW Indiana.

Proposed graticule shift

In this map the approximate border of Chicago, as well as the borders of relevant counties are in black, the division between the four graticules are in red, and the shifted graticule is in blue

Chicago is not entirely in one graticule. The northern part shares a second graticule with much of the suburbs, Kenosha, and southern Milwaukee. Since this graticule is mostly Lake Michigan, it will be rare that it gets to meet. The Chicago graticule also excludes many of the suburbs. A possible solution to this problem would be using a shifted graticule divided on the half-degree lines extending from 41.5 to 42.5 degrees north and from 87.5 to 88.5 degrees west. This would be a smaller proportion lake than either of the two Chicago graticules. It would also be almost entirely contained within Illinois. The proposed area would include very nearly all of Cook County, as well as all of DuPage and Lake Counties, most of Kane, Kendall, McHenry, and Will Counties, and very small parts of Indiana and Wisconsin. This would include all the important cities of the Chicago area, including Chicago, Aurora, Elgin, Evanston, Joliet, Naperville, Schaumburg, and Waukegan. It would exclude Kenosha and Gary, but they are in other states. Also, this would separate Chicago from Milwaukee.

Four-graticule proposal

Another possible solution would be, in addition to the Chicago graticule, to consider the three graticules immediately to the west, northwest, and north of it, and out of those four locations, select whichever is closest to the city center (and is not underwater). This solution was first proposed by "Gylbert" on the xkcd Blag, though in relation to Calgary, not Chicago. See the Gylbert Algorithm.

Alternate simple solutions

On days when the meeting point falls within Lake Michigan, meetings are moved horizontally and only horizontally to the nearest beach. This allows for more reachable locations (Metra helps here) and more frequent meetups.

Likewise, on days when the hash point falls in the lake, use the hash point in the graticule directly to the west.

Official Meetup

In accordance with the Main Page, the official meetup of the 41,-87 graticule will be held every Saturday at 4pm Central time.

• The first Saturday meetup (05-24-2008): Happened! But only one person showed.

• The meetup for (06-07-2008): Four of us drove down from the city. Nice little spot right off of the road. We were a few minutes late and did not see anyone else there. Pictures were taken but they remain on a cell phone that I do not have access to.

• The meetup for (06-21-2008): Five people total showed up at the suggested alternate location, a beach near Uptown.

• Planning meetup for (07-25-2009)

Other Visits

If you visited a point on a date/time other than Saturday at 4:00 PM, put it here.

• 2009-03-27 41 -87: Solo geohasher excursion by Nathan to the middle of a corn field north of Manteno, IL.
• Bored on Thanksgiving '08 (11-27-2008): Just me out in the burbs somewhere.

External Links

• Official Geohashing Coordinate Calculator - compute today's geohashed coordinates (available only after 10:30am Central).
• Official Atom feed for 41,-87