Exhibit 10.13

SUPPLEMENTAL RETIREMENT BENEFIT PLAN

This Supplemental Retirement Benefit Plan (the “Plan”) as adopted effective as
of November 12, 1991, and amended August 24, 1997 and March 4, 1999, by Mosinee
Paper Corporation, a Wisconsin corporation, (“Mosinee”) for the purposes of
providing deferred compensation in the form of supplemental retirement benefits
for San W. Orr, Jr.  (“Mr. Orr”) in recognition of his service to Mosinee as its
Chairman of the Board of Directors is hereby further amended as of this 16th day
of December, 2005, effective as of January 1, 2005.

1.

Normal Supplemental Retirement Benefit.  Beginning on the first day of the first
month following the last to occur of (a) Mr. Orr’s termination of employment
with each of Mosinee, its parent, Wausau Paper Corp. (“Wausau”), and each other
member of the Controlled Group (as hereinafter defined) of which Wausau is also
a member or (b) Mr. Orr’s 60th birthday, and continuing on the first day of each
succeeding month, Mosinee shall pay to Mr. Orr, if he is then living, a monthly
supplemental retirement benefit (Mr. Orr’s “Normal Supplemental Retirement
Benefit”) in an amount equal to 50% of one-twelfth of Mr. Orr’s highest final
average W-2 compensation for the five consecutive calendar year period in which
such compensation was paid.  Mr. Orr’s Normal Supplemental Retirement Benefit
shall not be reduced or offset by the amount of any other payment then due him
from Mosinee or any other plan or program now or hereafter maintained by
Mosinee.  For purposes of this Plan, the term “Controlled Group” means Wausau
and each other member of the controlled group of corporations or other entities
under common control to which Wausau belongs for purposes of determining whether
a separation from service has occurred pursuant to Section 409A of the Internal
Revenue Code of 1984, as amended, and the regulations promulgated thereunder.

2.

Surviving Spouse Benefit.  From and after the first day of the first month
following the later of (a) the month in which Mr. Orr’s death occurs or (b) the
month in which Mr. Orr would have attained his 60th birthday if Mr. Orr’s death
occurs before he has attained age 60, and continuing on the first day of each
succeeding month, Mosinee shall pay to Mr. Orr’s spouse, if then living (Mr.
Orr’s “Surviving Spouse”), a monthly benefit (the “Supplemental Surviving Spouse
Benefit”) in an amount equal to 50% of the Normal Supplemental Retirement
Benefit to which Mr. Orr would have then been entitled had he then been living.

3.

Change in Control of Wausau.

(a)

In the event a Change in Control of Wausau occurs prior to Mr. Orr’s death,
Mosinee shall pay to Mr. Orr a lump sum amount equal to the present value of Mr.
Orr’s Normal Supplemental Retirement Benefit, as determined hereunder, as of the
first day of the first month following such Change in Control of Wausau on which
Mr. Orr is neither an employee nor a director of Wausau or of any other member
of the Controlled Group of which Wausau is a member, whether or not such Change
in Control occurred prior to the date on which Mr. Orr shall have ceased to be
an employee or a director of Wausau.  Upon payment of the lump sum amount
provided for in this subparagraph (a), Mosinee shall have no further obligation
to pay any benefits under this Plan.

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(b)

In the event a Change in Control of Wausau occurs after Mr. Orr’s death and
whether or not the Supplemental Surviving Spouse Benefit shall have then become
payable, Mosinee shall pay to Mr. Orr’s Surviving Spouse, if then living, the
present value of the unpaid Supplemental Surviving Spouse Benefit. Upon payment
of the lump sum amount provided for in this subparagraph (b), Mosinee shall have
no further obligation to pay any benefits under this Plan.

(c)

For purposes of this plan, a “Change in Control of Wausau” shall be mean the
happening of any of the following events:

(1)

The acquisition by any individual, entity or group (within the meaning of
Section 13(d)(3) or 14(d)(2) of the Exchange Act (a “Person”) of beneficial
ownership (within the meaning of Rule 13d-3 promulgated under the Exchange Act)
of 20% or more of either (A) the then outstanding shares of common stock of
Wausau (the “Outstanding Corporation Common Stock”) or (B) the combined voting
power of the then outstanding voting securities of Wausau entitled to vote
generally in the election of directors (the “Outstanding Corporation Voting
Securities”); excluding, however, the following: (i) any acquisition directly
from Wausau other than an acquisition by virtue of the exercise of a conversion
privilege unless the security being so converted was itself acquired directly
from Wausau, (ii) any acquisition by Wausau, (iii) any acquisition by any
employee benefit plan (or related trust) sponsored or maintained by Wausau or
any entity controlled by Wausau, (iv) any acquisition pursuant to a transaction
which complies with clauses (A), (B), and (C) of paragraph (3) of this Section
3(c), (v) except as provided in paragraphs (4) and (5), any acquisition by any
of the Woodson Entities or any of the Smith Entities, or (vi) any increase in
the proportionate number of shares of Outstanding Corporation Common Stock or
Outstanding Corporation Voting Securities beneficially owned by a Person to 20%
or more of the shares of either of such classes of stock if such increase was
solely the result of the acquisition of Outstanding Corporation Common Stock or
Outstanding Corporation Voting Securities by Wausau; provided, however, that
this clause (vi) shall not apply to any acquisition of Outstanding Corporation
Common Stock or Outstanding Corporation Voting Securities not described in
clauses (1), (ii), (iii), (iv), or (v) of this paragraph (1) by the Person
acquiring such shares which occurs after such Person had become the beneficial
owner of 20% or more of either the Outstanding Corporation Common Stock or
Outstanding Corporation Voting Securities by reason of share purchases by
Wausau; or

(2)

A change in the composition of the Board such that the individuals who, as of
the Effective Date, constitute the Board (such Board shall be hereinafter
referred to as the “Incumbent Board”) cease for any reason to constitute at
least a majority of the Board; provided, however, for purposes of the Plan, that
any individual who becomes a member of the Board subsequent to the Effective
Date whose election, or nomination for election by Wausau’s shareholders, was
approved by a vote of at least a majority of those individuals who are members
of

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the Board and who were also members of the Incumbent Board (or deemed to be such
pursuant to this proviso) shall be deemed to be and shall be considered as
though such individual were a member of the Incumbent Board, but provided,
further, that any such individual whose initial assumption of office occurs as a
result of either an actual or threatened election contest (as such terms are
used in Rule 14a-11 of Regulation 14A promulgated under the Exchange Act) or
other actual or threatened solicitation of proxies or consents by or on behalf
of a Person other than the Board shall not be so deemed or considered as a
member of the Incumbent Board; or

(3)

Consummation of a reorganization, merger or consolidation, or sale or other
disposition of all or substantially all of the assets of Wausau or the
acquisition of the assets or securities of any other entity (a “Corporate
Transaction”); excluding, however, such a Corporate Transaction pursuant to
which (A) all or substantially all of the individuals and entities who are the
beneficial owners, respectively, of the Outstanding Corporation Common Stock and
Outstanding Corporation Voting Securities immediately prior to such Corporate
Transaction will beneficially own, directly or indirectly, more than 60% of,
respectively, the outstanding shares of common stock and the combined voting
power of the then outstanding voting securities entitled to vote generally in
the election of directors, as the case may be, of the corporation  resulting
from such Corporate Transaction (including, without limitation, a corporation
which as a result of such transaction owns or all or substantially all of
Wausau’s assets either directly or through one or more subsidiaries) (the
“Resulting Corporation”) in substantially the same proportions as their
ownership, immediately prior to such Corporate Transaction, of the Outstanding
Corporation Common Stock and Outstanding Corporation Voting Securities, as the
case may be, (B) no Person (other than Wausau, any employee benefit plan (or
related trust) of Wausau, any Woodson Entity, any Smith Entity, or such
Resulting Corporation) will beneficially own, directly or indirectly, 20% or
more of, respectively, the outstanding shares of common stock of the Resulting
Corporation or the combined voting power of the then outstanding voting
securities of such Resulting Corporation entitled to vote generally in the
election of directors except to the extent that such ownership existed with
respect to Wausau prior to the Corporate Transaction, and (C) individuals who
were members of the Incumbent Board will constitute at least a majority of the
members of the board of directors of the Resulting Corporation; or

(4)

The Woodson Entities acquire beneficial ownership of more than 35% of the
Outstanding Corporation Common Stock or Outstanding Corporation Voting
Securities or of the outstanding shares of common stock or the combined voting
power of the then outstanding voting securities entitled to vote generally in
the election of directors, as the case may be, of the Resulting Corporation; or

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(5)

The Smith Entities acquire beneficial ownership of more than 35% of the
Outstanding Corporation Common Stock or Outstanding Corporation Voting
Securities or of the outstanding shares of common stock or the combined voting
power of the then outstanding voting securities entitled to vote generally in
the election of directors, as the case may be, of the Resulting Corporation; or

(6)

The approval by the shareholders of Wausau of a complete liquidation or
dissolution of Wausau.

For purposes of this Section 3(c), the term “Woodson Entities” shall mean
Aytchmonde P. Woodson, Leigh Yawkey Woodson and Alice Richardson Yawkey, members
of their respective families and their respective descendants (the “Woodson
Family”), heirs or legatees of any of the Woodson Family members, transferees by
will, laws of descent or distribution or by operation of law of any of the
foregoing (including of any such transferees) (including any executor or
administrator of any estate of any of the foregoing), any trust established by
any of Aytchmonde P. Woodson, Leigh Yawkey Woodson, or Alice Richardson Yawkey,
whether pursuant to last will or otherwise, any partnership, trust or other
entity established primarily for the benefit of, or any other Person the
beneficial owners of which consist primarily of, any of the foregoing or any
Affiliates or Associates of any of the foregoing or any charitable trust or
foundation to which any of the foregoing transfers or may transfer securities of
Wausau (including any beneficiary or trustee, partner, manager or director of
any of the foregoing or any other Person serving any such entity in a similar
capacity).

For purposes of this Section 3(c), the term “Smith Entities” shall mean David B.
Smith and Katherine S. Smith, members of their respective families and their
respective descendants (the “Smith Family”), heirs or legatees of any of the
Smith Family members, transferees by will, laws of descent or distribution or by
operation of law of any of the foregoing (including of any such transferees)
(including any executor or administrator of any estate of any of the foregoing),
any trust established by either of David B. Smith or Katherine S. Smith, whether
pursuant to last will or otherwise, any partnership, trust or other entity
established primarily for the benefit of, or any other Person the beneficial
owners of which consist primarily of, any of the foregoing or any Affiliates or
Associates of any of the foregoing or any charitable trust or foundation to
which any of the foregoing transfers or may transfer securities of Wausau
(including any beneficiary or trustee, partner, manager or director of any of
the foregoing or any other Person serving any such entity in a similar
capacity).

For purposes of this Section 3(c), the terms “Affiliate” and “Associate” shall
have the meanings ascribed to such terms in Rule 12b-2 of the General Rules and
Regulations under the Exchange Act as in effect on the date of this Plan.

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(e)

For purposes of this Plan, the present value of Mr. Orr’s Normal Supplemental
Retirement Benefit or the Supplemental Surviving Spouse Benefit shall be
determined by reference to the 1983 Individual Annuity Mortality Table with an
assumed interest rate equal to the “immediate annuity rate” as then in effect as
determined by the Pension Benefit Guaranty Corporation and promulgated in
Appendix B to 29 C.F.R. '2619.65 or any successor regulation adopted for the
same or substantially similar purpose.

4.

Supplemental Retirement Benefits in Addition to Other Rights and Benefits.  The
rights and benefits conferred upon Mr. Orr (and Mr. Orr’s Surviving Spouse)
pursuant to this Plan shall be in addition to all other rights and benefits
conferred upon Mr. Orr by Mosinee by reason of his employment.

5.

Nature of Mosinee’s Obligations and Mr. Orr’s Rights. Neither Mr. Orr nor his
Surviving Spouse, if any, shall acquire any right, title or interest in the
assets of Mosinee by reason of this Plan.  To the extent Mr. Orr or his
Surviving Spouse shall acquire a right to receive payments from Mosinee pursuant
to this Plan, such right shall be no greater than the right of any unsecured
general creditor of Mosinee.

6.

Assignment by Mr. Orr Prohibited.  This Plan and Mr. Orr’s rights and benefits
hereunder (and the rights of his surviving spouse, if any) shall not be subject
to voluntary or involuntary sale, pledge, hypothecation, transfer or assignment
by Mr. Orr or such Surviving Spouse, their personal representatives or heirs or
any other person or persons or organization or organizations succeeding to any
of their rights and benefits hereunder.

7.

Funding.  All benefits paid or payable pursuant to the terms of this Plan shall
be paid out of the general assets of Mosinee.

8.

Claims Procedure.  The claims procedure set forth in the Wausau Paper Corp.
Retirement Plan or any successor to such plan is incorporated herein by this
reference as the claims procedure for this Plan.

9.

Plan Administrator.  The plan administrator and named fiduciary of this Plan
shall be Mosinee.

10.

Binding Effect.  This Plan shall be binding upon and inure to the benefit of (1)
Mr. Orr and his Surviving Spouse and their personal representatives and heirs
and any other person or persons or organization or organizations succeeding to
any of Mr. Orr’s rights or benefits hereunder, and (2) Mosinee and its
successors and assigns.

11.

Severability.  The invalidity or unenforceability of any provision of this Plan
shall not invalidate or render unenforceable any other provision of this
agreement.

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12.

Governing Law.  This Plan shall be governed by the Employee Retirement Income
Security Act of 1974, as amended, and to the extent not preempted by such Act,
by the laws of the State of Wisconsin.

13.

Section 409A Compliance.  Notwithstanding any other provisions of the Plan, no
distribution otherwise provided for by this Plan shall be made if such
distribution would cause the Plan to fail to meet the requirements of Section
409A of the Internal Revenue Code of 1986, as amended (the “Code”) and cause the
Participant to be subject to the interest and additional tax imposed pursuant to
Code Section 409A(a)(1)(B), and any such distribution shall be modified so that
such distribution will then comply with the requirements of Code Section 409A so
as to preclude the application of Code Section 409A(a)(1)(B); including, if
required, the deferral of any distribution for a period of not less than six
months following the Termination of Employment of a Participant who was a key
employee, as determined pursuant to Code Section 409A.

IN WITNESS WHEREOF, Mosinee has caused this agreement to be executed by its
President thereunto duly authorized as of the 12th day of December, 2005.

MOSINEE PAPER CORPORATION

By: THOMAS J. HOWATT

Thomas J. Howatt

As its President and Chief Executive Officer

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AMENDMENTS TO THE

SUPPLEMENTAL RETIREMENT BENEFIT PLAN FOR SAN W. ORR, JR.

ORIGINALLY ADOPTED NOVEMBER 12, 1991

Under authority granted by resolution of the Compensation Committee of the Board
of Directors of Wausau Paper Corp. dated December 15, 2005, the undersigned
officer hereby adopts the following amendments to the Supplemental Retirement
Benefit Plan for San W. Orr, Jr., which was originally adopted November 12, 1991
and last amended December 16, 2005.

Paragraph 1 shall be amended by substituting the phrase “Section 409A of the
Internal Revenue Code of 1986, as amended (the “Code”)” for the phrase “Section
409A of the Internal Revenue Code of 1984, as amended” where it appears therein.

Paragraph 3(c) shall be amended in its entirety to read as follows effective
January 1, 2005:

“For purposes of this plan, a “Change in Control of Wausau” shall mean a “change
of control” of Wausau as defined in Code Section 409A and the regulations
promulgated thereunder.”

Dated this 20th day of November, 2008.

STUART R. CARLSON

Stuart R. Carlson

Executive Vice President, Administration