[KevinDavis]

Chicago is famous for dyeing the Chicago River green on St. Patrick's Day. The tradition began in 1962, when a pipe fitters union—with the permission of the mayor—poured a hundred pounds (45 kilograms) of green vegetable dye into the river. (On the job, the workers often use colored dyes to track illegal sewage dumping.) Today only 40 pounds (18 kilograms) of dye are used, enough to turn the river green for several hours.

According to the Friends of the Chicago River, a local environmental group, more people are likely to view the Chicago River on St. Patrick's Day than on any other day.

The Chicago River is green year round..

[missyme]

So is Savannah GA..They also dye the River Green