POWER OF ATTORNEY

Know all by these presents, that the undersigned hereby constitutes
and appoints each of Stacy Loretz-Congdon, Amy Morgan and Vicky Fong,
or either of them signing singly, and with full power of substitution,
the undersigned's true and lawful attorney-in-fact to:

(1) execute for and on behalf of the undersigned, in the undersigned's
capacity as an officer and/or director of Core-Mark Holding Company,
Inc. (the "Company"), Forms 3, 4, and 5 in accordance with Section 16(a)
of the Securities Exchange Act of 1934 and the rules thereunder;

(2) do and perform any and all acts for and on behalf of the
undersigned which may be necessary or desirable to complete and
execute any such Form 3, 4, or 5, complete and execute any amendment
or amendments thereto, and timely file such form with the SEC and
any stock exchange or similar authority; and

(3) take any other action of any type whatsoever in connection with
the foregoing which, in the opinion of such attorney-in-fact, may be
of benefit to, in the best interest of, or legally required by, the
undersigned, it being understood that the documents executed by such
attorney-in-fact on behalf of the undersigned pursuant to this Power
of Attorney shall be in such form and shall contain such terms and
conditions as such attorney-in-fact may approve in such attorney-in-
fact's discretion.

The undersigned hereby grants to each such attorney-in-fact full power
and authority to do and perform any and every act and thing whatsoever
requisite, necessary, or proper to be done in the exercise of any of
the rights and powers herein granted, as fully to all intents and
purposes as the undersigned might or could do if personally present,
with full power of substitution or revocation, hereby ratifying and
confirming all that such attorney-in-fact, or such attorney-in-fact's
substitute or substitutes, shall lawfully do or cause to be done by
virtue of this power of attorney and the rights and powers herein granted.
The undersigned acknowledges that the foregoing attorneys-in-fact, in
serving in such capacity at the request of the undersigned, are not
assuming, nor is the Company assuming, any of the udnersigned's
responsibilities to comply with Section 16 of the Securities Exchange
Act of 1934.

This Power of Attorney shall remain in full force and effect until
the undersigned is no longer required to file Forms 3, 4, and 5 with
respect to the undersigned's holdings of and transactions in securities
issued by the Company, unless earlier revoked by the undersigned in a
signed writing delivered to the foregoing attorneys-in-fact.

IN WITNESS WHEREOF, the undersigned has caused this Power of Attorney
to be executed as of this 11 day of August, 2008.

Stuart Booth
Signature