POWER OF ATTORNEY


	WHEREAS, directors, certain officers, and beneficial owners of
more than 10% of any equity security of AMEREN CORPORATION, a
Missouri corporation (herein referred to as the "Company"), as well as
certain directors and officers of Company subsidiaries, are required to file
with the Securities and Exchange Commission and the New York Stock
Exchange, under Section 16 of the Securities Exchange Act of 1934, as
now and hereafter amended, statements regarding ownership and change in
ownership of equity securities of the Company (the "Reporting Forms");
and

	WHEREAS, the undersigned holds an office or offices in the
Company and/or Company subsidiaries and is required to file such
Reporting Forms.

	NOW, THEREFORE, the undersigned hereby constitutes and
appoints Steven R. Sullivan and/or Ronald K. Evans and/or G. L. Waters
and/or any individual who hereafter holds the offices of Secretary or
Assistant Secretary of the Company the true and lawful attorneys-in-fact
of the undersigned, for and in the name, place and stead of the undersigned,
to affix the name of the undersigned (including, without limitation, any
electronic signature) to said Reporting Forms and any amendments thereto,
and, for the performance of the same acts, each with power to appoint in
their place and stead and as their substitute, one or more attorneys-in-fact
for the undersigned, with full power of revocation; hereby ratifying and
confirming all that said attorneys-in-fact may do by virtue hereof.  The
undersigned acknowledges that the foregoing attorney-in-fact, in serving in
such capacity at the request of the undersigned, are not assuming, nor is
the Company assuming, any of the undersigned's responsibilities to comply
with Section 16 of the Securities Exchange Act of 1934.  The undersigned
further acknowledges that in whatever capacities he/she may hold in the
Company and/or its subsidiaries in the future, this Power of Attorney shall
remain in full force and effect until such time it would be revoked by the
undersigned.

	IN WITNESS WHEREOF, the undersigned has hereunto set his/her hand
this 2nd day of September, 2003:


            	                         /s/ Douglas R. Oberhelman
				         ----------------------------------
                                             Douglas R. Oberhelman


STATE OF ILLINOIS   )
          	    ) SS.
COUNTY OF PEORIA    )

	On this 2nd day of September, 2003, before me, the undersigned Notary
Public in and for said State, personally appeared Douglas R. Oberhelman, known
to me to be the person described in and who executed the foregoing power of
attorney and acknowledged to me that he/she executed the same as his/her free
 act and deed for the purposes therein stated.

	IN TESTIMONY WHEREOF, I have hereunto set my hand and affixed my
official seal.


				           /s/ Tinkie E. Demmin
                                           ----------------------------------
				               Tinkie E. Demmin
				               Official Seal
				               Tinkie E. Demmin
			                   Notary Public - State of Illinois
			                   My Commission Expires:  06-09-07