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                                                                    Exhibit 10.3

                  TAX SEPARATION AND INDEMNIFICATION AGREEMENT

          This TAX SEPARATION AND INDEMNIFICATION AGREEMENT (the "Agreement"),
dated _____________, 2003, is by and among Alliant Energy Corporation, a
Wisconsin corporation ("Alliant Energy"), Alliant Energy Resources, Inc., a
Wisconsin corporation ("Resources"), Whiting Petroleum Corporation, a Delaware
corporation ("WPC"), Whiting Oil and Gas Corporation, a Delaware corporation
("Whiting"), and three wholly-owned subsidiaries of Whiting: Whiting-Golden Gas
Corporation, an Oklahoma corporation, Whiting Programs, Inc., a Delaware
corporation and WOK Acquisition Company, a Delaware corporation (the three
subsidiaries are collectively referred to as "Whiting Subs").

                                    PREAMBLE:

          WHEREAS, Resources, Whiting and Whiting Subs have been members of an
affiliated group of corporations filing consolidated federal income tax returns
of which Alliant Energy is the common parent (the "Alliant Energy Group") and
filing certain state, local and foreign income or franchise tax returns on a
combined, consolidated, unitary or other similar basis (such federal, state,
local and foreign tax returns are collectively referred to as the "Consolidated
Returns");

          WHEREAS, Alliant Energy, Resources, Whiting and Whiting Subs are
parties to the Alliant Energy Corporation Tax Allocation Agreement (the "Tax
Allocation Agreement"), which became effective for tax years ending on or after
December 31, 1999;

          WHEREAS, WPC is acquiring all of the outstanding stock of Whiting from
Resources (the "Transfer") pursuant to the Master Separation Agreement dated
_________, 2003, by and among WPC, Whiting, Resources and Alliant Energy;

          WHEREAS, upon consummation of the Closing (as such term is defined
below), Whiting, Whiting Subs and WPC will become members of an affiliated group
of corporations (the "Buyer Group") and Whiting and Whiting Subs will cease to
be members of the Alliant Energy Group; and

          WHEREAS, the parties wish to assign responsibility for the preparation
and filing of tax returns; to set forth the methodology for determining their
respective liabilities for Taxes (as such term is defined below) and for
allocating such liabilities among themselves for all Taxes that may be owed to
or assessed by the Internal Revenue Service or any other comparable state, local
or foreign governmental authority attributable to the periods before, after
and/or including the Closing Date (as such term is defined below); to establish
procedures for reimbursing one party for Taxes allocated to the other under this
Agreement; and to provide for certain tax elections and for the division of any
tax benefits which may arise as a result of such elections.

          NOW, THEREFORE, in consideration of the mutual covenants and
agreements hereinafter set forth, the parties hereby agree as follows:

     1.   Definitions. For purposes of this Agreement, the following terms shall
be defined as follows:

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          1.1  "Actual Tax Liability" has the meaning specified in Section 1.32
hereof.

          1.2  "Alliant Energy" means Alliant Energy Corporation, a Wisconsin
corporation.

          1.3  "Alliant Energy Group" has the meaning specified in the Preamble
of this Agreement.

          1.4  "AMT Credits" has the meaning specified in Section 1.20 hereof.

          1.5  "Buyer" means WPC and any successors thereto.

          1.6  "Buyer Group" has the meaning specified in the Preamble of this
Agreement.

          1.7  "Change of Control" means the occurrence of any one or more of
the following events subsequent to the Closing Date: (i) the acquisition by an
individual, entity or other "person" (within the meaning of Section 13(d)(3) or
14(d)(2) of the Securities Exchange Act of 1934, as amended (the "Exchange
Act")) (a "Person") of beneficial ownership (within the meaning of Rule 13d-3
promulgated under the Exchange Act) of 50% or more of either (a) the outstanding
shares of common stock of Buyer (the "Outstanding Buyer Common Stock") or (b)
the combined voting power of the then outstanding voting securities of Buyer
entitled to vote generally in the election of directors (the "Outstanding Buyer
Voting Securities"); (ii) the acquisition by any Person, other than Buyer, of
beneficial ownership (within the meaning of Rule 13d-3 promulgated under the
Exchange Act) of 50% or more of either (a) the then outstanding shares of common
stock of Whiting (the "Outstanding Whiting Common Stock") or (b) the combined
voting securities of Whiting entitled to vote generally in the election of
directors (the "Outstanding Whiting Voting Securities"); (iii) any
reorganization (including, but not limited to, transactions described in Section
368(a) of the Code), merger, share exchange, or consolidation involving Buyer or
any subsidiary of Buyer (each, a "Buyer Merger"), unless, immediately following
any such Buyer Merger (a) more than 50% of the then Outstanding Buyer Common
Stock and 50% of the then Outstanding Buyer Voting Securities are then
beneficially owned, directly or indirectly, by Persons who were the beneficial
owners, respectively, of the Outstanding Buyer Common Stock and the Outstanding
Buyer Voting Securities immediately prior to such Buyer Merger and (b) no Person
beneficially owns (within the meaning of Rule 13d-3 promulgated under the
Exchange Act) 25% or more of either (1) the then Outstanding Buyer Common Stock
or (2) the then Outstanding Buyer Voting Securities; or (iv) any reorganization
(including, but not limited to, transactions described in section 368(a) of the
Code), merger, share exchange, or consolidation involving Whiting (each, a
"Whiting Merger"), unless immediately following any such Whiting Merger, Buyer
beneficially owns, directly or indirectly, at least 80% of the Outstanding
Whiting Common Stock and 80% of the Outstanding Whiting Voting Securities.

          1.8  "Closing" means the closing of the Transfer and the immediate
sale of more than 50% of the stock of WPC to underwriters by Resources.

          1.9  "Closing Date" means the date on which the Closing occurs.

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          1.10 "Code" means the Internal Revenue Code of 1986, as amended. All
section references to the Code also include any successor sections thereto.

          1.11 "Consolidated Returns" has the meaning specified in the Preamble
of this Agreement, and the term "Consolidated Return" means any one of the
Consolidated Returns.

          1.12 "Disputed Amount" has the meaning specified in Section 9.3.3
hereof.

          1.13 "Estimated Tax Payment Date" means any of the dates specified in
Section 6655 of the Code for the payment of Buyer's estimated U.S. federal
income tax.

          1.14 "Interim Period" has the meaning specified in Section 3.1 hereof.

          1.15 "Lump Sum Record Date" means the last day of Buyer's taxable year
which includes the 10th anniversary of the Closing Date.

          1.16 "Lump Sum Payment Date" means the Return Due Date for the taxable
year which ends on the Lump Sum Record Date.

          1.17 "Lump Sum Tax Benefit Amount" has the meaning specified in
Section 8.6 hereof.

          1.18 "Notional Tax Liability" has the meaning specified in Section
1.32 hereof.

          1.19 "Other Returns" has the meaning specified in Section 2.2 hereof.

          1.20 "Realized Section 29 Tax Credits" has the meaning specified in
Section 7.1 hereof.

          1.21 "Resources" means Alliant Energy Resources, Inc., a Wisconsin
corporation.

          1.22 "Returns" means all returns, declarations, reports, statements
and other documents required to be filed in respect of Taxes, and the term
"Return" means any one of the foregoing Returns.

          1.23 "Return Due Date" means the date specified in Section 6072 of the
Code for the filing of Buyer's income tax returns, as may be validly extended by
Buyer pursuant to the automatic extension procedure under the Code and the
regulations thereunder.

          1.24 "Section 29 Tax Credits" means the tax credits under Section 29
of the Code attributable to Whiting's and Whiting Subs' activities during the
taxable year ending on December 31, 2002 that were not utilized in the Alliant
Energy Group's U.S. Consolidated Return for taxable year 2002. The amount of
such Section 29 Tax Credits is approximately $___________ (such amount subject
to the adjustment by the IRS or otherwise). By operation of the corporate
alternative minimum tax, the Section 29 Tax Credits carry over to Alliant Energy
Group's U.S. Consolidated Return for taxable year ending on December 31, 2003
and future years as part of the Alliant Energy Group's alternative minimum tax
credits. The Alliant Energy

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Group's alternative minimum tax credits generated in taxable year 2002 are
referred to as the "AMT Credits."

          1.25 "Section 338(h)(10) Election" has the meaning specified in
Section 4 hereof.

          1.26 "Short Period" has the meaning specified in Section 3.1 hereof.

          1.27 "Tax" means any one of the Taxes. "Taxes" means all federal,
state, local and foreign taxes, including interest and penalties, on, based on,
measured by, or with respect to, income, net income, net worth or capital
(including without limitation the Michigan single business tax); provided that
Taxes shall not include deferred income taxes.

          1.28 "Tax Allocation Agreement" has the meaning specified in the
Preamble of this Agreement.

          1.29 "Tax Authority" means the Internal Revenue Service or any other
comparable state, local or foreign governmental authority.

          1.30 "Tax Benefit Base Amount" for any Taxable Period means (i) any
increase in an amortization, depreciation, expense or loss deduction in such
Taxable Period or any decrease in an item of income or gain in such Taxable
Period attributable to, or as a result of, the basis adjustments due to the
Section 338(h)(10) Election, including any basis increases attributable to, or
as a result of, payments made pursuant to this Agreement, (ii) any portion of
payments made pursuant to this Agreement characterized as interest or original
issue discount for tax purposes, or (iii) any increase in any net operating or
capital loss carryover or carryback or tax credit that is carried to such
Taxable Period and that arose or arises in a prior or subsequent Taxable Period
as a result of any such increase in deduction or decrease in income or gain
under (i) or (ii) in such prior or subsequent Taxable Period.

          1.31 "Tax Benefit Issue" has the meaning specified in Section 9.3.1
hereof.

          1.32 "Tax Benefits" means, for any Taxable Period, the excess, if any,
of (a) the total amount of U.S. federal, state, local and foreign income and
franchise taxes that would be payable by Whiting or any other member of the
Buyer Group in respect of such Taxable Period if the Tax Benefit Base Amount for
such Taxable Period were not taken into account ("Notional Tax Liability"), over
(b) the total amount of U.S. federal, state, local and foreign income and
franchise taxes payable by Whiting or any other member of the Buyer Group in
respect of such Taxable Period after taking into account the Tax Base Benefit
Amount for such Taxable Period (the "Actual Tax Liability"); provided, however,
that the Tax Benefits for any Taxable Period shall be no less than the Tax
Benefits calculated without giving effect to any items of income, gain, expense,
loss, deduction, credit or related carryovers or carrybacks directly
attributable to or related to any businesses, assets or liabilities other than
(i) the businesses conducted by Whiting or any other member of the Buyer Group
prior to Closing, (ii) any assets held by Whiting or any other member of the
Buyer Group immediately prior to Closing and (iii) any liabilities of Whiting or
any other member of the Buyer Group immediately prior to Closing (the "Minimum
Tax Benefits"). Any Tax Benefits hereunder shall be determined using the method
of reporting (i.e., consolidated, combined or separate returns)

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actually utilized by Whiting or the particular member of the Buyer Group. In any
Taxable Period ending prior to or on the date of a Change of Control, the Tax
Benefits shall equal the amount calculated as provided above in this Section
1.32. In any Taxable Period ending subsequent to a Change of Control, the Tax
Benefits shall be the greater of (i) the Tax Benefits calculated as if a Change
of Control had not occurred, with the Notional Tax Liability and the Actual Tax
Liability calculated by including only items of income, gain, expense, loss,
deduction, credit and related carryovers and carrybacks directly attributable or
related to the businesses conducted by Whiting or any other member of the Buyer
Group prior to the Change of Control (the "Historic Businesses") and excluding
all items of income, gain, expense, loss, deduction, credit or related
carryovers or carrybacks not attributable or related to the Historic Businesses
as conducted by Whiting or any other member of the Buyer Group prior to the
Change of Control (including, without limitation, any interest expense incurred
by Whiting or any other member of the Buyer Group after the Change of Control,
whether or not to a related person, or any fees, expenses or other charges to
any related person unless directly related to the Historic Businesses as
conducted by Whiting or any other member of the Buyer Group prior to the Change
of Control), (ii) the excess of the Notional Tax Liability over the Actual Tax
Liability, calculated by including all items of income, gain, expense, loss,
deduction, credit and related carryovers and carrybacks of any corporation or
group of corporations filing a federal or other consolidated, combined or
unitary income or franchise tax return entitled to the Tax Benefit Base Amount,
and (iii) the Minimum Tax Benefits.

          1.33 "Taxable Period" means any taxable year (or portion thereof)
ending after the Closing Date.

          1.34 "Transfer" has the meaning specified in the Preamble of this
Agreement.

          1.35 "Underpayment Rate" has the meaning specified in Section 9.3.2
hereof.

          1.36 "Whiting" means Whiting Oil and Gas Corporation, a Delaware
corporation.

          1.37 "Whiting Subs" means Whiting-Golden Gas Corporation, an Oklahoma
corporation, Whiting Programs, Inc., a Delaware corporation, and WOK Acquisition
Company, a Delaware corporation.

          1.38 "WPC" means Whiting Petroleum Corporation, a Delaware
corporation.

     2.   Preparation and Filing of Tax Returns.

          2.1  Preparation. Alliant Energy shall prepare or cause to be prepared
all Consolidated Returns with respect to Whiting and Whiting Subs and the
Returns set forth on Schedule A attached hereto, but only for taxable periods
ending on, prior to, or including the Closing Date. Buyer, Whiting and Whiting
Subs shall prepare or cause to be prepared all other Returns of Buyer, Whiting
and Whiting Subs. Buyer, Whiting and Whiting Subs shall prepare or cause to be
prepared work papers and schedules with respect to Whiting and Whiting Subs
setting forth all of the information necessary for Alliant Energy to properly
prepare any Consolidated Return or other return set forth on Schedule A
consistent with past practices on a timely basis. All such Returns shall be
prepared using accounting methods, tax elections and tax

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positions as determined by Alliant Energy in its sole discretion, but only for
taxable periods ending on, prior to, or including the Closing Date.

          2.2  Filing. Alliant Energy shall file or cause to be filed all
Consolidated Returns with respect to Whiting and Whiting Subs for taxable
periods ending on, prior to, or including the Closing Date. Buyer, Whiting and
Whiting Subs shall file or cause to be filed all other Returns of Buyer, Whiting
and Whiting Subs ("Other Returns"), including those set forth on Schedule A.

     3.   Obligation for Taxes. Except as provided in Section 4 of this
Agreement, Buyer, Whiting and Whiting Subs shall be responsible for all Taxes of
Buyer, Whiting and Whiting Subs.

          3.1  Taxes Due with Respect to Consolidated Returns. Alliant Energy
shall pay or cause to be paid timely all Taxes on behalf of Whiting and Whiting
Subs that are due with respect to the Consolidated Returns for taxable periods
ending on, prior to or including the Closing Date. With the exception of the Tax
liability on the deemed asset sale as a result of the Section 338(h)(10)
Election (as set forth in Section 4 of this Agreement), Buyer, Whiting and
Whiting Subs shall reimburse Alliant Energy for (i) Whiting's and Whiting Subs'
portions of the U.S. federal consolidated income tax of the Alliant Energy Group
in accordance with the Tax Allocation Agreement as if each of Whiting and
Whiting Subs remained a "member of the Group" as set forth therein, and (ii)
Whiting's and Whiting Subs' portions of all other Taxes on such Consolidated
Returns using similar principles and procedures as used in the Tax Allocation
Agreement to determine a member's portion of the U.S. federal consolidated
income tax liability of the Alliant Energy Group. Such Taxes shall be determined
by closing Whiting's and Whiting Subs' books and records as of and including the
Closing Date, or if the allocation of an item of income, gain, expense, loss,
deduction, credit or related carryovers or carrybacks cannot be definitely
allocated to an ascertainable date, such item shall be pro rated on a daily
basis. The parties hereto will, to the extent permitted by applicable law, elect
with the relevant Tax Authority to treat for all purposes the Closing Date as
the last day of a taxable period of Whiting and Whiting Subs. The period January
1, 2003, through and including the Closing Date shall be treated as a "Short
Period" for purposes of this Agreement. In any case where applicable law does
not permit Whiting or Whiting Subs to treat the Closing Date as the last day of
a Short Period, then for purposes of this Agreement, Buyer, Whiting and Whiting
Subs shall pay all such Taxes that are attributable to the operation of Whiting
and Whiting Subs for such Interim Period (as defined below) as follows: (i) in
the case of Taxes that are not based in whole or in part on income or gross
receipts, the total amount of such Taxes for the period in question multiplied
by a fraction, the numerator of which is the total number of days in the Interim
Period, and the denominator of which is the total number of days in the entire
period in question, and (ii) in the case of Taxes that are based in whole or in
part on income or gross receipts, the Taxes that would be due with respect to
the Interim Period, if such Interim Period were a Short Period. "Interim Period"
means, with respect to any Taxes imposed on Whiting or Whiting Subs for which
the Closing Date is not the last day of a Short Period, the period of time
beginning on the first day of the actual taxable period that includes the
Closing Date and ending on and including the Closing Date.

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          3.2  Taxes Due with Respect to Other Returns. Buyer, Whiting and
Whiting Subs shall pay or cause to be paid timely to the relevant Tax Authority
all Taxes that are due with respect to the Other Returns, including those set
forth on Schedule A.

     4.   Section 338(h)(10) Election. Buyer and Alliant Energy and, if
necessary, Resources, Whiting, and/or Whiting Subs, shall timely make or cause
to be made a valid joint election under Section 338(h)(l0) of the Code and
equivalent elections under comparable state, local or foreign law as may be
requested by Alliant Energy (in its sole discretion) relating to the Transfer
(collectively, the "Section 338(h)(10) Election"). Buyer, Whiting, Whiting Subs,
Alliant Energy and Resources shall each file, or cause to be filed, their
federal Tax Returns treating the Transfer as a sale of the assets of Whiting and
Whiting Subs followed by a liquidation pursuant to Section 338(h)(10) of the
Code. If an equivalent election is made for state, local or foreign Tax
purposes, the parties shall each file on a similar basis all of their state,
local and foreign Tax Returns. Buyer, Whiting and Whiting Subs shall timely
assist Alliant Energy in making the Section 338(h)(10) Election, including
without limitation, completing all relevant forms, schedules, and other
documents and all Tax Returns reflecting the Section 338(h)(10) Election.
Notwithstanding anything to the contrary contained in the Tax Allocation
Agreement, Alliant Energy shall be responsible for the Taxes resulting from the
deemed asset sale on account of the Section 338(h)(10) Election. If a Section
338(h)(10) Election is made, Buyer, Whiting and Whiting Subs shall cause each
partnership (and each entity taxed as a partnership for Tax purposes) in which
any of them has an interest to make an election under Section 754 of the Code to
the extent such election maximizes the amount of Tax Benefits and the Lump Sum
Tax Benefit Amount to be paid to Resources as determined by Alliant Energy or
Resources in their sole discretion.

     5.   Valuation and Allocation of Consideration. The parties agree that the
"aggregate deemed sale price" and "adjusted grossed-up basis" (as such terms are
defined in the regulations under Section 338 of the Code) and similar terms
under the relevant state, local or foreign law with respect to the Transfer and
Section 338(h)(10) Election shall be determined by Alliant Energy, such
determination to be made, in part, based on the sales price per share of the
common stock of Buyer to the underwriters. The value of the consideration shall
be allocated among the assets of Whiting and Whiting Subs as indicated on a
schedule to be prepared by Buyer or Whiting within 90 days after the Closing
Date, subject to the review, approval and adjustment by Alliant Energy, which
review, approval and adjustment shall include, but is not limited to, making
necessary adjustments to make the allocations consistent with any post-Closing
Date adjustments; provided, however, that any adjustments to the initial
schedule prepared by Buyer or Whiting shall be mutually agreed to by Buyer or
Whiting, on the one hand, and Alliant Energy, on the other. The parties (i)
shall be bound by such allocation as set forth on such final schedule mutually
agreed to by the parties for purposes of determining any Taxes and (ii) shall
prepare and file all Returns in a manner consistent with such allocation as set
forth on such final schedule mutually agreed to by the parties. In the event
that any Tax Authority disputes such allocation, the party receiving notice of
such dispute shall promptly notify and consult with the other parties hereto
concerning resolution of such dispute.

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     6.   Subsequent Assessments or Refunds.

          6.1  Tax Adjustment Relating to Consolidated Returns. In the event
there is an adjustment with respect to a Consolidated Return for a taxable
period ending on, prior to or including the Closing Date subsequent to the
preparation of such Return and payment and reimbursement of the Taxes shown as
due thereon, Alliant Energy shall pay or cause to be paid any Taxes and be
entitled to receive all refunds of Taxes. If, as a result of the adjustment,
additional Tax is due, then Buyer, Whiting and Whiting Subs shall reimburse
Alliant Energy the portion of such Tax due attributable to Whiting or Whiting
Subs calculated using the same principles as set forth in Section 3.1 hereof
within ten (10) days after notice thereof. If, as a result of the adjustment,
the Alliant Energy Group is entitled to a Tax refund, then Alliant Energy shall
pay to Buyer, Whiting or Whiting Subs the portion of such Tax refund
attributable to Whiting or Whiting Subs calculated in the same manner as Tax
liabilities are calculated as set forth in Section 3.1 hereof within ten (10)
days after receipt thereof.

          6.2  Tax Adjustment Relating to Other Returns. In the event there is
an adjustment with respect to the Other Returns subsequent to the preparation of
such Returns and payment of the Taxes due, Buyer, Whiting and Whiting Subs shall
pay or cause to be paid any Taxes and be entitled to receive all refunds of
Taxes with respect to such Other Returns.

     7.   Section 29 Tax Credits.

          7.1  Realized Section 29 Tax Credits. "Utilized AMT Credits" means,
for any taxable period ending after the Closing Date, an amount equal to the
excess, if any, of (a) the total amount of U.S. federal income tax that would be
payable by the Alliant Energy Group in respect to such taxable period if the AMT
Credits were not taken into account, over (b) the total amount of U.S. federal
income tax payable by the Alliant Energy Group in respect to such taxable period
taking into account the AMT Credits (if any) for such taxable period in
accordance with the Code and the regulations thereunder. For purposes of
determining whether the AMT Credits are taken into account for such taxable
period for purpose of calculating Utilized AMT Credits and the amount of AMT
Credits remaining under this Agreement, the alternative minimum tax credits
(including the AMT Credits) generated from the earliest year shall be deemed to
be used first (i.e., on a First-In-First-Out basis). Realized Section 29 Tax
Credits shall mean an amount equal to the Utilized AMT Credits multiplied by a
fraction, the numerator of which is the difference between the Section 29
Credits less cumulative amounts paid by Alliant under this Section 7.1 (as may
be adjusted under Section 7.2) and the denominator of which is the difference
between the AMT Credits less cumulative amounts of Utilized AMT Credits. Within
ten (10) days after Alliant Energy files or causes to be filed its U.S.
Consolidated Return for a taxable period ending after the Closing Date, Alliant
Energy shall, in lieu of any other payment under any agreement among the
parties, pay to Buyer, Whiting or Whiting Subs an amount equal to the Realized
Section 29 Tax Credits (if any) for such taxable period. Buyer, Whiting and
Whiting Subs hereby acknowledge and agree that the Alliant Energy Group may not
be able to utilize its AMT Credits until taxable year 2008 or later.
Consequently, the amount of Realized Section 29 Tax Credits may be zero until
taxable year 2008 or later.

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          7.2  Tax Adjustment Relating to Realized Section 29 Tax Credits. If,
as a result of an adjustment, the amount of the Realized Section 29 Tax Credits
for a taxable period is less than the amount as computed under Section 7.1
hereof (or as recomputed under this Section 7.2), then Buyer, Whiting and
Whiting Subs shall pay Alliant Energy the difference within ten (10) days of
notice thereof. If, as a result of an adjustment, the amount of the Realized
Section 29 Tax Credits for a taxable period is more than the amount as computed
under Section 7.1 hereof (or as recomputed under this Section 7.2), then Alliant
Energy shall pay Buyer, Whiting or Whiting Subs the difference within ten (10)
days of its discovery thereof.

          7.3  Payment with respect to Realized Section 29 Tax Credits. Any
amount that Alliant Energy is obligated to pay to Buyer, Whiting or Whiting Subs
under this Section 7 shall first be offset by the amount that Buyer, Whiting and
Whiting Subs are obligated to pay Alliant Energy or Resources under this
Agreement.

          7.4  Tax Credit Accounting. Alliant Energy shall prepare and deliver
or cause to be prepared and delivered to Buyer, Whiting or Whiting Subs, no more
than 60 days after it files a U.S. federal Consolidated Return, a good faith
accounting of the amounts, if any, of the AMT Credits utilized in such
Consolidated Return, the amounts, if any, of the AMT Credits that have not been
utilized, the Section 29 Tax Credits, and the Realized Section 29 Tax Credits.
Alliant Energy's accounting obligation shall terminate after the sum of the
amounts paid to Buyer under Sections 7.1 and 7.2 hereof and the amounts subject
to offset under Section 7.3 hereof equals the Section 29 Tax Credits.

     8.   Tax Benefit Sharing Payment to Resources.

          8.1  Return Due Date Payments. Except as set forth in Section 8.6,
with respect to each Taxable Period, Buyer, Whiting, or Whiting Subs shall pay
to Resources, on the appropriate Return Due Date for such Taxable Period, an
amount equal to 90% of the amount of the Tax Benefits for the Taxable Period,
together with accrued interest at the Underpayment Rate determined as follows:
interest shall accrue on 22.5% (or, in the case of a Taxable Period of less than
one year, 90% divided by the number of Estimated Tax Payment Dates in such
Taxable Period) of the Tax Benefits with respect to a Taxable Period beginning
on each Estimated Tax Payment Date with respect to such Taxable Period until
paid.

          8.2  Current Amount Adjustment. To the extent that the amounts paid to
Resources pursuant to Section 8.1, this Section 8.2 and Section 9.3.2 (excluding
amounts for interest and penalties) hereof for a Taxable Period exceed the sum
of 90% of the amount of the actual Tax Benefits (as may be amended or
recomputed, as the case may be), such excess amounts paid shall be paid to
Buyer, Whiting or Whiting Subs by Resources. To the extent that the amounts paid
to Resources pursuant to Section 8.1, this Section 8.2 and Section 9.3.2
(excluding amounts for interest and penalties) hereof for a Taxable Period are
less than 90% of the amount of the actual Tax Benefits (as may be amended or
recomputed, as the case may be), such deficit in amounts shall be paid to
Resources by Buyer, Whiting or Whiting Subs. All amounts due under this Section
8.2 shall be paid within ten (10) days of the time Buyer files its U.S. federal,
state, local or foreign income, franchise, or other Tax Return for the Taxable
Period (or amended returns, claims for refund or other modifications to taxable
income).

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          8.3  Tax Computation Assumptions. The Tax Benefits hereunder shall be
calculated separately for U.S. federal, state, local and foreign Tax purposes.
When allocation or apportionment factors are required for any Tax computation,
the factors used in Whiting's or the affected member of the Buyer Group's most
recently filed Returns or Returns as filed (as appropriate) in the relevant
jurisdictions shall be used if actual allocation or apportionment factors are
not readily available.

          8.4  Prohibited Transactions by Buyer, Whiting and Whiting Subs.
Buyer, Whiting and every member of the Buyer Group shall not (i) enter into any
transactions a significant purpose of which is to reduce the amount of the Tax
Benefits or the Lump Sum Tax Benefit Amount otherwise payable to Resources under
this Agreement, (ii) enter into any transactions which may result in the
disqualification or invalidation of the Section 338(h)(10) Election, which
transactions include but are not limited to the merger, liquidation, conversion
or other corporate transactions involving Whiting or Whiting Subs that may
result in the Internal Revenue Service or any other Tax Authority disqualifying
or invalidating any Section 338(h)(10) Election, or (iii) sell, distribute or
otherwise dispose of any assets of Buyer (including the stock of Whiting
acquired pursuant to the Master Separation Agreement), Whiting or Whiting Subs
other than assets disposed of by Buyer, Whiting or Whiting Subs in the ordinary
course of business.

          8.5  Tax Benefit Estimates. With respect to each Taxable Period ending
on or prior to the Lump Sum Record Date, Buyer, Whiting and Whiting Subs shall
prepare and deliver or cause to be prepared and delivered to Resources, no less
than 60 days prior to the end of each calendar year, a good faith estimate of
the amount of the Tax Benefits that will be payable to Resources during the
immediately following year. Buyer, Whiting and Whiting Subs shall in good faith
revise and update or cause to be revised and updated each such estimate on a
quarterly basis, to be delivered to Resources no less than 15 days prior to the
end of each quarter.

          8.6  Tax Benefit Termination Payment. Buyer, Whiting and other members
of the Buyer Group shall, on the Lump Sum Payment Date, pay Resources the
present value of 90% of all the Tax Benefits with respect to all Taxable Periods
ending after the Lump Sum Record Date (the "Lump Sum Tax Benefit Amount"). The
Lump Sum Tax Benefit Amount shall be calculated by projecting future Tax
Benefits using all relevant data, business plans, engineering and geological
studies, tax rates and other provisions of the tax law in effect (and giving
effect to any changes thereto for the Taxable Periods such changes are scheduled
to become effective) and by assuming that each of Whiting and other members of
the Buyer Group has income or gain in all relevant Taxable Periods in excess of
all available depreciation, amortization, losses and other deductions, thereby
maximizing the Tax Benefits for each such Taxable Period. In determining the
present value of the future projected Tax Benefits amount, (i) the projected Tax
Benefits for all Taxable Periods ending on or before the fourth anniversary of
the Lump Sum Record Date shall be discounted using the short-term applicable
federal rate (compounding annually) effective on the Lump Sum Payment Date as
published by the Internal Revenue Service under Section 1274(d) of the Code,
(ii) the projected Tax Benefits for all Taxable Periods ending after the fourth
anniversary and on or before the tenth anniversary of the Lump Sum Record Date
shall be discounted using the mid-term applicable federal rate (compounding
annually) effective on the Lump Sum Payment Date as published by the Internal
Revenue Service under Section 1274(d) of the Code, and (iii) the projected Tax
Benefits for all

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Taxable Periods ending after the tenth anniversary of the Lump Sum Record Date
shall be discounted using the long-term applicable federal rate (compounding
annually) effective on the Lump Sum Payment Date as published by the Internal
Revenue Service under Section 1274(d) of the Code. For purposes of computing the
discounted Tax Benefits for each Taxable Period, such Tax Benefits shall be
assumed to be earned ratably throughout the year and shall be discounted to the
Lump Sum Payment Date. Buyer, Whiting and Whiting Subs' payment of the Lump Sum
Tax Benefit Amount pursuant to this Section 8.6 shall relieve the obligation of
Buyer, Whiting and other members of the Buyer Group to make Tax Benefit payments
with respect to Taxable Periods ending after the Lump Sum Record Date under
Sections 8.1 and 8.2 hereof but shall not affect any other aspect of this
Agreement.

     9.   Matters Arising After the Closing Date.

          9.1   Cooperation. Buyer, Whiting and any affected member of the Buyer
Group shall consult in good faith and provide Resources and Alliant Energy with
such assistance as reasonably may be requested in writing by any of them in
connection with (i) the preparation and execution of any Return, (ii) the
determination of the Tax Benefit Base Amount, the Notional Tax Liability, the
Actual Tax Liability and the estimate of the amount of the Tax Benefits and any
adjustment thereof, (iii) the negotiation and settlement of any audit or other
examination of any Return by any Tax Authority, or (iv) the handling of any
judicial or administrative proceeding relating to any Tax liability or taxable
periods of Whiting or Whiting Subs ending on, prior to, or including the Closing
Date, including without limitation to (i) notify Resources and Alliant Energy of
any Tax Authority's initiating an audit, requesting information or proposing
adjustment, or any extension of statutes of limitation and of final
determinations of adjustment, (ii) preserve records, documents and other
information relevant to liabilities for Taxes until the expiration of the
applicable statute of limitations or extensions thereof and to provide, upon
written request, copies of such records and/or reasonable access thereto, (iii)
make available without charge at a location determined by Buyer, Whiting or
Whiting Subs during normal working hours, upon written request, personnel
responsible for preparing, maintaining, or explaining information, records and
documents in connection with matters relating to Taxes, and (iv) execute and
deliver such powers of attorney, consents and other documents as are necessary
to carry out the intent of this Agreement.

          9.2   Discretion to Contest, Negotiate and Settle. Alliant Energy
shall have sole and exclusive discretion to contest or not to contest, negotiate
and settle proposed adjustments relating to the inclusion in any Consolidated
Return of the income, gain, expense, loss, deduction, credit, related carryovers
or carrybacks, or other tax items of Whiting and Whiting Subs for any period
ending on, prior to, or including the Closing Date. Buyer shall have sole and
exclusive discretion to contest or not to contest, negotiate and settle proposed
adjustments relating to the inclusion in all other Returns of the income, gain,
expense, loss, deduction, credit, related carryovers or carrybacks, or other tax
items of Whiting and Whiting Subs, except as set forth in Section 9.3 hereof.

          9.3   Disputed Tax Benefits.

          9.3.1 Control of Proceedings. In the event that the Internal Revenue
Service or other Tax Authority disputes the existence or amount of the Tax
Benefits (a "Tax Benefit

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<PAGE>

Issue"), Buyer, Whiting and any other affected member of the Buyer Group shall
contest the matter on audit, through Internal Revenue Service or other
administrative proceedings and through judicial proceedings. Representatives of
Alliant Energy or Resources shall be allowed to participate in such proceedings
in so far as they relate to the Tax Benefit Issue and such participation shall
be reflected by the grant of appropriate powers of attorney. Decisions regarding
the conduct of a contest shall be made by Alliant Energy or Resources or its
representatives after consultation with Buyer and its representatives; provided,
however, that ultimate control over contesting the Tax Benefit Issue, including
control over procedural matters that necessarily relate to all issues being
contested (including, without limitation, choice of forum), shall be exercised
in good faith by Alliant Energy or Resources and its representatives and Buyer,
Whiting and any other affected member of the Buyer Group shall take any action
as is necessary to effectuate the decisions of Alliant Energy or Resources;
provided, further, however, that decisions relating solely to tax issues
unrelated to the Tax Benefit Issue shall be made as set forth in Section 9.2
hereof. Decisions regarding the settlement of a contest of the Tax Benefit Issue
shall be made in good faith jointly by Alliant Energy (and Resources) and Buyer
(and Whiting and Whiting Subs) and their representatives; provided, however,
that if Alliant Energy (or Resources) or Buyer (or Whiting or Whiting Subs)
decline a settlement proposal relating to the Tax Benefit Issue that the other
wishes to accept, the contest will continue and the declining party will (i)
bear all further contest costs, (ii) indemnify the party wishing to accept the
settlement against any outcome more adverse than that of the proposed settlement
and (iii) be entitled to all benefits more advantageous than those of the
proposed settlement.

          9.3.2 Outcome of Contest and Repayment.

                A.  Adverse Outcome. If, as the result of a contest described in
Section 9.3.1 hereof, Tax Benefits are less than those taken into account in
computing any payments made under Section 8 hereof, such payments shall be
recomputed on the basis of such revised Tax Benefits, and any excess payments
shall be paid by Resources to Buyer, Whiting or any other member of the Buyer
Group, within ten (10) days after such contest is over. Resources shall also pay
to Buyer, Whiting or any other member of the Buyer Group interest at the rates
required to be paid by Buyer, Whiting or such other member of the Buyer Group
under Section 6621 of the Code (the "Underpayment Rate") with respect to the
revision of the amount of Tax Benefits or at the corresponding state, local or
foreign underpayment interest rates in connection with revisions relating to the
state, local or foreign tax revisions also within ten (10) days after the
contest is over.

                B.  Favorable Outcome. If, as the result of a contest described
in Section 9.3.1 hereof, Tax Benefits are more than those taken into account in
computing any payments made under Section 8 hereof, such payments shall be
recomputed on the basis of such revised Tax Benefits, and any deficit in payment
amounts shall be paid by Buyer, Whiting and other members of the Buyer Group to
Resources within ten (10) days after such contest is over. Buyer, Whiting and
other members of the Buyer Group shall also pay to Resources interest at the
rates Buyer, Whiting or other members of the Buyer Group are entitled to under
Section 6611 of the Code with respect to the revision of the amount of Tax
Benefits or at the corresponding state, local or foreign overpayment interest
rates in connection with revisions relating to the state, local or foreign tax
revisions, also within ten (10) days after the contest is over.

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          9.3.3 Resolution of Computational Disputes. If the parties hereto are
unable to agree on the amount of Tax Benefits or the Lump Sum Tax Benefit Amount
(the "Disputed Amount") as determined under Sections 1.32, 8.1, 8.2, 8.3 and 8.6
hereof, the determination of such Disputed Amount shall be made by an
independent firm of certified public accountants jointly selected by Resources
and Whiting. If Resources and Whiting cannot agree on the selection of an
independent firm of certified public accountants, such firm will be jointly
selected by the firms of certified public accountants that certify (or selected
by the firm of certified public accountants that certifies) the financial
statements of Resources and Buyer and that are other than the selecting firm(s).
Such accountants shall be given access by Resources, Buyer and their respective
subsidiaries to all information necessary to determine the Disputed Amount,
subject to the agreement of such accountants that such information shall be kept
confidential and shall not be released without the written consent of Resources
or Buyer, as appropriate, except as compelled by legal process. Any amount
otherwise due under this Agreement that is a Disputed Amount shall be paid,
together with interest at the Underpayment Rate from the date on which such
payment was originally due, within ten (10) days of the determination of such
Disputed Amount. Judgment upon the Disputed Amount as determined by the
accountants may be entered in any court having jurisdiction over the matter.
Each of Resources and Buyer (and its subsidiaries) shall pay its own costs and
expenses incurred in determining the Disputed Amount. Resources and Buyer shall
share equally the costs of the independent firm of certified public accountants
selected to determine the Disputed Amount.

          9.3.4 Expenses. Unless otherwise provided in the Agreement, fees and
expenses paid to third-party service providers and incurred after the date
hereof by Resources, Buyer or any of their subsidiaries for the purpose of
resolving any dispute relating to the Tax Benefits, including, without
limitation, legal and accounting expenses relating to the resolution of any
dispute with any Tax Authority regarding a Tax Benefit Issue or any related
activity, shall be borne by Resources in the lesser of the following percentages
(i) 90% or (ii) the Tax Benefits in controversy relating to a Tax Benefit Issue
divided by the total Tax in controversy relating to such Tax Benefit Issue. All
other such fees and expenses shall be borne by Buyer. Notwithstanding the above,
the obligation of Resources to bear any portion of such fees or expenses related
to service providers not retained by it shall be contingent upon Resources'
prior written approval of the retention of any such service providers.

     10.  Attorney's Fees. Should suit be brought to enforce or interpret any
part of the Agreement, the prevailing party will be entitled to recover, as an
element of the costs of suit and not as damages, reasonable attorneys' fees
actually incurred by such prevailing party (including, without limitation,
costs, expenses and fees on any appeal). The prevailing party will be entitled
to recover its costs of suit, regardless of whether such suit proceeds to final
judgment.

     11.  Notice of Change of Control. Buyer shall notify Resources in writing
of any Change of Control within 30 days of the occurrence of such Change of
Control and shall promptly provide Resources with all information in Buyer's
possession relating to such Change of Control as Resources may reasonably
request. Notwithstanding any other provision of this Agreement, Resources may
elect, by delivering written notice to Buyer within 90 days after its receipt of
the aforementioned notice from Buyer, to have such Change of Control not deemed
a "Change of Control" for purposes of this Agreement. Resources shall have the
right to make such an election with respect to any Change of Control.

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     12.  Construction. Each of the parties further agrees that notwithstanding
anything to the contrary contained herein, the provisions of this Agreement in
all events shall be interpreted and applied in a manner consistent with the
following principle: Alliant Energy shall be compensated for 90% of any tax
savings arising from (i) the increase in basis of the assets of Whiting and
Whiting Subs due to the Section 338(h)(10) Election and (ii) the payments
pursuant to this Agreement.

     13.  Notices. Any notice required under any provisions of this Agreement
shall be made in the manner provided in the section entitled "Notices" in the
Master Separation Agreement. Delivery of notice to Buyer shall be deemed to be
delivery of notice to Whiting and Whiting Subs.

     14.  Governing Law. This Agreement shall be governed by and construed in
accordance with the law of the state of Wisconsin applicable to contracts made
and to be performed therein, without effect to its choice of law.

     15.  Binding Effect; Successors. This Agreement shall be binding upon and
inure to the benefit of any successor, by merger, acquisition of assets or
otherwise, to any of the parties hereto (including but not limited to any
successor of Alliant Energy, Resources, Buyer, Whiting or Whiting Subs
succeeding to the tax attributes of Alliant Energy, Resources, Buyer, Whiting or
Whiting Subs under Section 381 of the Code), to the same extent as if such
successor had been an original party to the Agreement. In addition, Buyer shall
cause any and all members of the Buyer Group to be bound by the Agreement to the
extent necessary to implement the Agreement. Moreover, in the event of any
acquisition of the assets of Whiting or Whiting Subs in which gain or loss is
not recognized, in whole or in part, for federal income tax purposes, Buyer,
Whiting and Whiting Subs shall ensure that any purchaser of such assets shall
assume the obligation set forth in this Agreement.

     16.  Severability. In the event that any term or provision of this
Agreement shall for any reason be held invalid, illegal or unenforceable in any
respect, such invalidity, illegality or unenforceability shall not affect any
other term or provision, to the extent the same shall have been held to be
invalid, illegal or unenforceable, had never been contained herein.

     17.  Headings. The headings in the sections of this Agreement are inserted
for convenience of reference only and shall not constitute a part hereof.

     18.  Waivers. No waiver of any breach or default hereunder shall be
considered valid unless in writing and signed by the party giving such waiver,
and no such waiver shall be deemed a waiver of any subsequent breach or default
of the same or similar nature.

     19.  Rules of Construction. Each of the parties hereto agrees that (a) the
normal rule of construction to the effect that any ambiguities are to be
resolved against the drafting party shall not be employed in the interpretation
or construction of this Agreement, and (b) no usage of trade, course of dealing,
course of performance or enforcement or surrounding circumstances shall be used
in interpreting or construing this Agreement.

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     20.  Counterparts. This Agreement may be executed simultaneously in two or
more counterparts, each of which shall be deemed an original, but all of which
together shall constitute one and the same instrument.

     21.  Entire Agreement. This Agreement, together with the Tax Allocation
Agreement, the Registration Rights Agreement and the Master Separation
Agreement, constitutes the entire agreement of the parties with respect to the
subject matter hereof, supersedes all prior agreements and understandings
between them, and may not be modified, amended or terminated except by a written
agreement signed by all of the parties hereto. In the event there is a conflict
between this Agreement and the Tax Allocation Agreement, this Agreement shall
control.

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<PAGE>

          IN WITNESS WHEREOF, the parties hereto have caused this Agreement to
be executed as of the date first above written.

                                        ALLIANT ENERGY CORPORATION

                                          By:   _____________________________
                                          Name: _____________________________
                                          Title:_____________________________

                                        ALLIANT ENERGY RESOURCES, INC.

                                          By:   _____________________________
                                          Name: _____________________________
                                          Title:_____________________________

                                        WHITING PETROLEUM CORPORATION

                                          By:   _____________________________
                                          Name: _____________________________
                                          Title:_____________________________

                                        WHITING OIL AND GAS CORPORATION

                                          By:   _____________________________
                                          Name: _____________________________
                                          Title:_____________________________

                                        WHITING-GOLDEN GAS CORPORATION

                                          By:   _____________________________
                                          Name: _____________________________
                                          Title:_____________________________

                                        WHITING PROGRAMS, INC.

                                          By:   _____________________________
                                          Name: _____________________________
                                          Title:_____________________________

                                        WOK ACQUISITION COMPANY

                                          By:   _____________________________
                                          Name: _____________________________
                                          Title:_____________________________

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