PROSPECTUS SUPPLEMENT DATED NOVEMBER 14, 1997 FOR THE ALLIED GROUP, INC. DIVIDEND REINVESTMENT AND STOCK PURCHASE PLAN The prospectus dated February 11, 1997 (the "Prospectus") for the ALLIED Group, Inc. Dividend Reinvestment and Stock Purchase Plan (the "Plan") is supplemented to reflect the information set forth below. You should keep this Prospectus Supplement with the Prospectus. 3-FOR-2 STOCK SPLIT The Company effected a 3-for-2 stock split on November 14, 1997, which increased the number of shares remaining to be issued under the Plan from 846,056 to 1,269,084.