Two full days after the Des Moines Register’s “exclusive” tip that Sen. Barack Obama would return to Iowa Thursday, the location and time of the event have not been released.

In the final weeks of the campaign, the majority of the Democratic presidential nominee’s public events have been large rallies.  Saturday in St. Louis, he attracted a crowd of as many as 100,000, according to other news organizations.  That same day, he attracted 75,000 to an event in Kansas City, just hours south of the Des Moines metro, where Thursday’s event will take place.

So far, the campaign has only said that “Senator Obama will hold an event in the Des Moines area on Thursday afternoon.”

Since bigger events take longer to plan (and release details) than smaller ones, here’s one possible location: the Iowa State Fairgrounds.  Sen. John Kerry drew a crowd of 15,000 — gigantic in 2004 terms — there on October 15, 2004.

Update: The Obama campaign has canceled Thursday’s event, citing the deteriorating health of the Illinois senator’s grandmother.