<PAGE>   1
                                                                     EXHIBIT 4.7

                               GUARANTEE AGREEMENT



                                 BY AND BETWEEN





                              GLACIER BANCORP, INC.



                                       AND



                            WILMINGTON TRUST COMPANY










                        DATED AS OF_______________, 2001


<PAGE>   2

                                TABLE OF CONTENTS
<TABLE>
<CAPTION>
                                                                                          PAGE
                                                                                          ----
<S>                                                                                       <C>

RECITALS.....................................................................................1

ARTICLE I. DEFINITIONS AND INTERPRETATION....................................................1

SECTION 1.1  DEFINITIONS AND INTERPRETATION..................................................1

ARTICLE II. TRUST INDENTURE ACT..............................................................5

SECTION 2.1  TRUST INDENTURE ACT; APPLICATION................................................5

SECTION 2.2  LISTS OF HOLDERS OF SECURITIES..................................................5

SECTION 2.3  REPORTS BY THE GUARANTEE TRUSTEE................................................5

SECTION 2.4  PERIODIC REPORTS TO GUARANTEE TRUSTEE...........................................5

SECTION 2.5  EVIDENCE OF COMPLIANCE WITH CONDITIONS PRECEDENT................................6

SECTION 2.6  EVENTS OF DEFAULT; WAIVER.......................................................6

SECTION 2.7  EVENT OF DEFAULT; NOTICE........................................................6

SECTION 2.8  CONFLICTING INTERESTS...........................................................6

ARTICLE III. POWERS, DUTIES AND RIGHTS OF GUARANTEE TRUSTEE..................................6

SECTION 3.1  POWERS AND DUTIES OF THE GUARANTEE TRUSTEE......................................6

SECTION 3.2  CERTAIN RIGHTS OF GUARANTEE TRUSTEE.............................................8

SECTION 3.3  NOT RESPONSIBLE FOR RECITALS OR ISSUANCE OF GUARANTEE..........................10

ARTICLE IV. GUARANTEE TRUSTEE...............................................................10

SECTION 4.1  GUARANTEE TRUSTEE; ELIGIBILITY.................................................10

SECTION 4.2  APPOINTMENT, REMOVAL AND RESIGNATION OF GUARANTEE TRUSTEES.....................10

ARTICLE V. GUARANTEE........................................................................11

SECTION 5.1  GUARANTEE......................................................................11

SECTION 5.2  WAIVER OF NOTICE AND DEMAND....................................................11

SECTION 5.3  OBLIGATIONS NOT AFFECTED.......................................................11

</TABLE>

                                       i

<PAGE>   3
<TABLE>
<S>                                                                                        <C>

SECTION 5.4  RIGHTS OF HOLDERS..............................................................12

SECTION 5.5  GUARANTEE OF PAYMENT...........................................................13

SECTION 5.6  SUBROGATION....................................................................13

SECTION 5.7  INDEPENDENT OBLIGATIONS........................................................13

ARTICLE VI. LIMITATION OF TRANSACTIONS; SUBORDINATION.......................................13

SECTION 6.1  LIMITATION OF TRANSACTIONS.....................................................13

SECTION 6.2  RANKING........................................................................14

ARTICLE VII. TERMINATION....................................................................14

SECTION 7.1  TERMINATION....................................................................14

ARTICLE VIII. INDEMNIFICATION...............................................................14

SECTION 8.1  EXCULPATION....................................................................14

SECTION 8.2  INDEMNIFICATION................................................................15

ARTICLE IX. MISCELLANEOUS...................................................................15

SECTION 9.1  SUCCESSORS AND ASSIGNS.........................................................15

SECTION 9.2  AMENDMENTS.....................................................................15

SECTION 9.3  NOTICES........................................................................16

SECTION 9.4  BENEFIT........................................................................16

SECTION 9.5  GOVERNING LAW..................................................................16

</TABLE>

                                       ii

<PAGE>   4



                              CROSS REFERENCE TABLE

<TABLE>
<CAPTION>
           SECTION OF TRUST INDENTURE                                SECTION OF
             ACT OF 1939, AS AMENDED                            GUARANTEE AGREEMENT
           --------------------------                           -------------------
            <S>                                                 <C>


                     310(a)                                            4.1(a)
                     310(b)                                         4.1(c), 2.8
                     310(c)                                        Not Applicable
                     311(a)                                            2.2(b)
                     311(b)                                            2.2(b)
                     311(c)                                        Not Applicable
                     312(a)                                            2.2(a)
                     312(b)                                            2.2(b)
                       313                                              2.3
                     314(a)                                             2.4
                     314(b)                                        Not Applicable
                     314(c)                                             2.5
                     314(d)                                        Not Applicable
                     314(e)                                        1.1, 2.5, 3.2
                     314(f)                                             3.2
                     315(a)                                            3.1(d)
                     315(b)                                             2.7
                     315(c)                                             3.1
                     315(d)                                            3.1(d)
                     316(a)                                        1.1, 2.6, 5.4
                     316(b)                                             5.3
                     317(a)                                             3.1
                     317(b)                                        Not Applicable
                     318(a)                                            2.1(b)
                     318(b)                                             2.1
                     318(c)                                            2.1(a)
</TABLE>

Note:   This Cross-Reference Table does not constitute part of this Guarantee
        Agreement and shall not affect the interpretation of any of its terms or
        provisions.


                                      iii

<PAGE>   5

                               GUARANTEE AGREEMENT

       THIS GUARANTEE AGREEMENT (this "Guarantee") dated as of ________, 2001,
is executed and delivered by GLACIER BANCORP, INC., a Delaware corporation (the
"Guarantor"), and WILMINGTON TRUST COMPANY, a Delaware banking corporation, as
trustee (the "Guarantee Trustee"), for the benefit of the Holders (as defined
herein) from time to time of the Trust Preferred Securities (as defined herein)
of Glacier Capital Trust I, a Delaware statutory business trust (the "Trust").

                                    RECITALS

       WHEREAS, pursuant to an Amended and Restated Trust Agreement (the "Trust
Agreement"), dated as of ________, 2001, among the trustees of the Trust named
therein, the Guarantor, as depositor, and the holders from time to time of
undivided beneficial interests in the assets of the Trust, the Trust is issuing
on the date hereof up to 1,400,000 Trust Preferred Securities, having an
aggregate liquidation amount of $35,000,000, designated the ________% Cumulative
Trust Preferred Securities (the "Trust Preferred Securities"); and

       WHEREAS, as incentive for the Holders to purchase the Trust Preferred
Securities, the Guarantor desires irrevocably and unconditionally to agree, to
the extent set forth in this Guarantee, to pay to the Holders of the Trust
Preferred Securities the Guarantee Payments (as defined herein) and to make
certain other payments on the terms and conditions set forth herein.

       NOW, THEREFORE, in consideration of the purchase by each Holder of Trust
Preferred Securities, which purchase the Guarantor hereby agrees shall benefit
the Guarantor, the Guarantor executes and delivers this Guarantee for the
benefit of the Holders.

                                   ARTICLE I
                         DEFINITIONS AND INTERPRETATION

SECTION 1.1    DEFINITIONS AND INTERPRETATION.

       In this Guarantee, unless the context otherwise requires:

       (a) capitalized terms used in this Guarantee but not defined in the
preamble above have the respective meanings assigned to them in this Section
1.1;

       (b) terms defined in the Trust Agreement as at the date of execution of
this Guarantee have the same meaning when used in this Guarantee, unless
otherwise defined in this Guarantee;

       (c) a term defined anywhere in this Guarantee has the same meaning
throughout;

       (d) all references to "the Guarantee" or "this Guarantee" are to this
Guarantee as modified, supplemented or amended from time to time;

       (e) all references in this Guarantee to Articles and Sections are to
Articles and Sections of this Guarantee, unless otherwise specified;


<PAGE>   6

       (f) a term defined in the Trust Indenture Act has the same meaning when
used in this Guarantee, unless otherwise defined in this Guarantee or unless the
context otherwise requires; and

       (g) a reference to the singular includes the plural and vice versa.

       "Affiliate" of any specified Person means any other Person directly or
indirectly controlling or controlled by or under direct or indirect common
control with such specified Person. For the purposes of this definition,
"control" when used with respect to any specified Person means the power to
direct the management and policies of such Person, directly or indirectly,
whether through the ownership of voting securities, by contract or otherwise;
and the terms "controlling" and "controlled" have meanings correlative to the
foregoing.

       "Authorized Officer" of a Person means any Person that is authorized to
bind such Person; provided, however, that the Authorized Officer signing an
Officers' Certificate given pursuant to Section 314(a)(4) of the Trust Indenture
Act shall be the principal executive, financial or accounting officer of such
Person.

       "Business Day" means any day other than a Saturday, Sunday, a day on
which federal or state banking institutions in the State of Montana or
Wilmington, Delaware are authorized or required by law, executive order or
regulation to close or a day on which the Corporate Trust Office of the
Guarantee Trustee is closed for business.

       "Corporate Trust Office" means the office of the Guarantee Trustee at
which the corporate trust business of the Guarantee Trustee shall, at any
particular time, be principally administered, which office at the date of
execution of this Guarantee is located at Rodney Square North, 1100 North Market
Street, Wilmington, Delaware 19890-0001, Attention: Corporate Trust
Administration.

       "Covered Person" means any Holder or beneficial owner of Trust Preferred
Securities.

       "Debentures" means the ________% Subordinated Debentures due ________,
2031, of the Debenture Issuer held by the Property Trustee of the Trust.

       "Debenture Issuer" means Guarantor, issuer of the Debentures under the
Indenture.

       "Distributions" has the same meaning as given in the Trust Agreement.

       "Event of Default" means a default by the Guarantor on any of its payment
or other obligations under this Guarantee.

       "Guarantor" means Glacier Bancorp, Inc., a Delaware corporation.

       "Guarantee Payments" means the following payments or distributions,
without duplication, with respect to the Trust Preferred Securities, to the
extent not paid or made by the Trust: (i) any accumulated and unpaid
Distributions (as defined in the Trust Agreement) that are required to be paid
on such Trust Preferred Securities, to the extent the Trust shall have funds
available therefor, (ii) the redemption price, including all accumulated and
unpaid Distributions to


                                       2
<PAGE>   7

but excluding the date of redemption (the "Redemption Price"), to the extent the
Trust has funds available therefor, with respect to any Trust Preferred
Securities called for redemption by the Trust, and (iii) upon a voluntary or
involuntary dissolution, winding-up or termination of the Trust (other than in
connection with the distribution of Debentures to the Holders in exchange for
Trust Preferred Securities as provided in the Trust Agreement), the lesser of
(a) the aggregate of the Liquidation Amount and all accumulated and unpaid
Distributions on the Trust Preferred Securities to the date of payment, to the
extent the Trust shall have funds available therefor, and (b) the amount of
assets of the Trust remaining available in either case for distribution to
Holders in liquidation of the Trust (the "Liquidation Distribution"). If an
event of default (as defined in the Indenture) with respect to the Debentures
has occurred and is continuing, the rights of holders of the Common Securities
(as defined in the Trust Agreement)(to receive payments under the Trust
Agreement are subordinated to the rights of Holders of Trust Preferred
Securities to receive Guarantee Payments.

       "Guarantee Trustee" means Wilmington Trust Company, until a Successor
Guarantee Trustee has been appointed and has accepted such appointment pursuant
to the terms of this Guarantee and thereafter means each such Successor
Guarantee Trustee.

       "Holder" shall mean any holder, as registered on the books and records of
the Trust, of any Trust Preferred Securities; provided, however, that, in
determining whether the holders of the requisite percentage of Trust Preferred
Securities have given any request, notice, consent or waiver hereunder, "Holder"
shall not include the Guarantor, the Guarantee Trustee or any of their
respective Affiliates.

       "Indemnified Person" means the Guarantee Trustee, any Affiliate of the
Guarantee Trustee, or any officers, directors, shareholders, members, partners,
employees, representatives, nominees, custodians or agents of the Guarantee
Trustee.

       "Indenture" means the Indenture dated as of ________, 2001, among the
Debenture Issuer and Wilmington Trust Company, as trustee, and any indenture
supplemental thereto pursuant to which certain subordinated debt securities of
the Debenture Issuer are to be issued to the Property Trustee of the Trust.

       "List of Holders" shall have the meaning assigned thereto in Section
2.2(a) hereof.

       "Liquidation Amount" means the stated value of $25.00 per Trust Preferred
Security.

       "Liquidation Distribution" has the meaning provided therefor in the
definition of Guarantee Payments.

       "Majority in Liquidation Amount of the Trust Preferred Securities" means,
except as provided in the terms of the Trust Preferred Securities or, except as
provided by the Trust Indenture Act, a vote by Holder(s) of Trust Preferred
Securities, voting separately as a class, of more than 50% of the Liquidation
Amount (including the stated amount that would be paid on redemption,
liquidation or otherwise, plus accumulated and unpaid Distributions to but
excluding the date upon which the voting percentages are determined) of all
Outstanding Trust Preferred Securities.


                                       3
<PAGE>   8

       "Officers' Certificate" means, with respect to any Person, a certificate
signed by two Authorized Officers of such Person, at least one of whom shall be
the principal executive officer, principal financial officer, principal
accounting officer, treasurer or any vice president of such Person. Any
Officers' Certificate delivered with respect to compliance with a condition or
covenant provided for in this Guarantee shall include:

       (a) a statement that each officer signing the Officers' Certificate has
read the covenant or condition and the definition relating thereto;

       (b) a brief statement of the nature and scope of the examination or
investigation undertaken by each officer in rendering the Officers' Certificate;

       (c) a statement that each such officer has made such examination or
investigation as, in such officer's opinion, is necessary to enable such officer
to express an informed opinion as to whether or not such covenant or condition
has been complied with; and

       (d) a statement as to whether, in the opinion of each such officer, such
condition or covenant has been complied with.

       "Person" means a legal person, including any individual, corporation,
estate, partnership, joint venture, association, joint stock company, limited
liability company, trust, unincorporated association, or government or any
agency or political subdivision thereof, or any other entity of whatever nature.

       "Redemption Price" has the meaning provided therefor in the definition of
Guarantee Payments.

       "Responsible Officer" means, with respect to the Guarantee Trustee, any
officer within the Corporate Trust Office of the Guarantee Trustee with direct
responsibility for the administration of this Guarantee, including any
vice-president, any assistant vice-president, any assistant secretary or other
officer or assistant officer of the Guarantee Trustee customarily performing
functions similar to those performed by any of the above designated officers and
also means, with respect to a particular corporate trust matter, any other
officer to whom such matter is referred because of that officer's knowledge of
and familiarity with the particular subject.

       "Subsidiary" means, with respect to any Person, (i) any corporation at
least a majority of whose outstanding Voting Stock shall at the time be owned,
directly or indirectly, by such Person or by one or more of its Subsidiaries or
by such Person and one or more of its Subsidiaries; (ii) any general
partnership, joint venture or similar entity, at least a majority of whose
outstanding partnership or similar interests shall at the time be owned by such
Person, or by one or more of its Subsidiaries, or by such Person and one or more
of its Subsidiaries; (iii) any limited partnership of which such Person or any
of its Subsidiaries is a general partner; and (iv) any limited liability
company, a majority of the membership interests of which are held by such Person
or one or more of its Subsidiaries.

       "Successor Guarantee Trustee" means a successor Guarantee Trustee
possessing the qualifications to act as Guarantee Trustee under Section 4.1.


                                       4
<PAGE>   9

       "Trust Indenture Act" means the Trust Indenture Act of 1939, as amended.

                                  ARTICLE II.

                               TRUST INDENTURE ACT

SECTION 2.1 TRUST INDENTURE ACT; APPLICATION.

       (a) This Guarantee is subject to the provisions of the Trust Indenture
Act that are required to be part of this Guarantee and shall, to the extent
applicable, be governed by such provisions.

       (b) If and to the extent that any provision of this Guarantee limits,
qualifies or conflicts with the duties imposed by Section 310 to 317, inclusive,
of the Trust Indenture Act, such imposed duties shall control.

SECTION 2.2 LISTS OF HOLDERS OF SECURITIES.

       (a) In the event the Guarantee Trustee is not also acting in the capacity
of the Property Trustee under the Trust Agreement, the Guarantor shall provide
or cause to be provided to the Guarantee Trustee a list, in such form as the
Guarantee Trustee may reasonably require, of the names and addresses of the
Holders of the Trust Preferred Securities ("List of Holders") as of the date (i)
within five (5) Business Days after the last day of March, June, September and
December, and (ii) at any other time within 30 days of receipt by the Guarantor
of a written request for a List of Holders as of a date no more than 15 days
before such List of Holders is given to the Guarantee Trustee; provided, that
the Guarantor shall not be obligated to provide such List of Holders at anytime
the List of Holders does not differ from the most recent List of Holders caused
to have been given to the Guarantee Trustee by the Guarantor. The Guarantee
Trustee may destroy any List of Holders previously given to it on receipt of a
new List of Holders.

       (b) The Guarantee Trustee shall comply with its obligations under
Sections 311(a), 311(b) and Section 312(b) of the Trust Indenture Act.

SECTION 2.3 REPORTS BY THE GUARANTEE TRUSTEE.

       On or before July 15 of each year, the Guarantee Trustee shall provide to
the Holders of the Trust Preferred Securities such reports as are required by
Section 313 of the Trust Indenture Act, if any, in the form and in the manner
provided by Section 313 of the Trust Indenture Act. The Guarantee Trustee shall
also comply with the requirements of Section 313(d) of the Trust Indenture Act.

SECTION 2.4 PERIODIC REPORTS TO GUARANTEE TRUSTEE.

       The Guarantor shall provide to the Guarantee Trustee such documents,
reports and information as required by Section 314 (if any) and the compliance
certificate required by Section 314 of the Trust Indenture Act in the form, in
the manner and at the times required by Section 314 of the Trust Indenture Act.


                                       5

<PAGE>   10

SECTION 2.5 EVIDENCE OF COMPLIANCE WITH CONDITIONS PRECEDENT.

       The Guarantor shall provide to the Guarantee Trustee such evidence of
compliance with any conditions precedent, if any, provided for in this Guarantee
that relate to any of the matters set forth in Section 314(c) of the Trust
Indenture Act, consisting of an Officers' Certificate and an opinion of counsel,
each containing the statements required by Sections 314(c) and 314(e) of the
Trust Indenture Act.


SECTION 2.6 EVENTS OF DEFAULT; WAIVER.

       The Holders of a Majority in Liquidation Amount of Trust Preferred
Securities may, by vote, on behalf of the Holders of all of the Trust Preferred
Securities, waive any past Event of Default and its consequences. Upon such
waiver, any such Event of Default shall cease to exist, and any Event of Default
arising therefrom shall be deemed to have been cured, for every purpose of this
Guarantee, but no such waiver shall extend to any subsequent or other default or
Event of Default or impair any right consequent thereon.

SECTION 2.7 EVENT OF DEFAULT; NOTICE.

       (a) The Guarantee Trustee shall, within five Business Days after the
occurrence of an Event of Default, transmit by mail, first class postage
prepaid, to the Holders of the Trust Preferred Securities, notices of all Events
of Default actually known to a Responsible Officer of the Guarantee Trustee,
unless such defaults have been cured before the giving of such notice; provided,
that, except in the case of a default by Guarantor on any of its payment
obligations, the Guarantee Trustee shall be protected in withholding such notice
if and so long as a Responsible Officer of the Guarantee Trustee in good faith
determines that the withholding of such notice is in the interests of the
Holders of the Trust Preferred Securities.

       (b) The Guarantee Trustee shall not be deemed to have knowledge of any
Event of Default unless the Guarantee Trustee shall have received written
notice, or a Responsible Officer charged with the administration of the Trust
Agreement shall have obtained written notice of such Event of Default.

SECTION 2.8 CONFLICTING INTERESTS.

       The Trust Agreement shall be deemed to be specifically described in this
Guarantee for the purposes of clause (i) of the first proviso contained in
Section 310(b) of the Trust Indenture Act.

                                  ARTICLE III.

                 POWERS, DUTIES AND RIGHTS OF GUARANTEE TRUSTEE

SECTION 3.1 POWERS AND DUTIES OF THE GUARANTEE TRUSTEE.

       (a) This Guarantee shall be held by the Guarantee Trustee for the benefit
of the Holders of the Trust Preferred Securities, and the Guarantee Trustee
shall not transfer this Guarantee to any Person except a Holder of Trust
Preferred Securities exercising his or her rights



                                       6
<PAGE>   11

pursuant to Section 5.4(b) or to a Successor Guarantee Trustee on acceptance by
such Successor Guarantee Trustee of its appointment to act as Successor
Guarantee Trustee. The right, title and interest of the Guarantee Trustee shall
automatically vest in any Successor Guarantee Trustee, and such vesting and
cessation of title shall be effective whether or not conveyancing documents have
been executed and delivered pursuant to the appointment of such Successor
Guarantee Trustee.

       (b) If an Event of Default actually known to a Responsible Officer of the
Guarantee Trustee has occurred and is continuing, the Guarantee Trustee shall
enforce this Guarantee for the benefit of the Holders of the Trust Preferred
Securities.

       (c) The Guarantee Trustee, before the occurrence of any Event of Default
and after the curing of all Events of Default that may have occurred, shall
undertake to perform only such duties as are specifically set forth in this
Guarantee, and no implied covenants shall be read into this Guarantee against
the Guarantee Trustee. In case an Event of Default has occurred (that has not
been cured or waived pursuant to Section 2.6) and is actually known to a
Responsible Officer of the Guarantee Trustee, the Guarantee Trustee shall
exercise such of the rights and powers vested in it by this Guarantee, and use
the same degree of care and skill in its exercise thereof, as a prudent Person
would exercise or use under the circumstances in the conduct of his or her own
affairs.

       (d) No provision of this Guarantee shall be construed to relieve the
Guarantee Trustee from liability for its own negligent action, its own negligent
failure to act, or its own willful misconduct, except that:

          (i) prior to the occurrence of any Event of Default and after the
       curing or waiving of all such Events of Default that may have occurred:

               (A) the duties and obligations of the Guarantee Trustee shall be
       determined solely by the express provisions of this Guarantee, and the
       Guarantee Trustee shall not be liable except for the performance of such
       duties and obligations as are specifically set forth in this Guarantee,
       and no implied covenants or obligations shall be read into this Guarantee
       against the Guarantee Trustee; and

               (B) in the absence of bad faith on the part of the Guarantee
       Trustee, the Guarantee Trustee may conclusively rely, as to the truth of
       the statements and the correctness of the opinions expressed therein,
       upon any certificates or opinions furnished to the Guarantee Trustee and
       conforming to the requirements of this Guarantee; but in the case of any
       such certificates or opinions that by any provision hereof are
       specifically required to be furnished to the Guarantee Trustee, the
       Guarantee Trustee shall be under a duty to examine the same to determine
       whether or not they conform to the requirements of this Guarantee;

          (ii) the Guarantee Trustee shall not be liable for any error of
       judgment made in good faith by a Responsible Officer of the Guarantee
       Trustee, unless it shall be proved that the Guarantee Trustee was
       negligent in ascertaining the pertinent facts upon which such judgment
       was made;


                                       7
<PAGE>   12

          (iii) the Guarantee Trustee shall not be liable with respect to any
       action taken or omitted to be taken by it in good faith in accordance
       with the direction of the Holders of not less than a Majority in
       Liquidation Amount of the Trust Preferred Securities relating to the
       time, method and place of conducting any proceeding for any remedy
       available to the Guarantee Trustee, or exercising any trust or power
       conferred upon the Guarantee Trustee under this Guarantee; and

          (iv) no provision of this Guarantee shall require the Guarantee
       Trustee to expend or risk its own funds or otherwise incur personal
       financial liability in the performance of any of its duties or in the
       exercise of any of its rights or powers, if the Guarantee Trustee shall
       have reasonable grounds for believing that the repayment of such funds or
       liability is not reasonably assured to it under the terms of this
       Guarantee or indemnity, reasonably satisfactory to the Guarantee Trustee,
       against such risk or liability is not reasonably assured to it.

SECTION 3.2 CERTAIN RIGHTS OF GUARANTEE TRUSTEE.

       (a) Subject to the provisions of Section 3.1:

          (i) the Guarantee Trustee may conclusively rely, and shall be fully
       protected in acting or refraining from acting upon, any resolution,
       certificate, statement, instrument, opinion, report, notice, request,
       direction, consent, order, bond, debenture, note, other evidence of
       indebtedness or other paper or document believed by it to be genuine and
       to have been signed, sent or presented by the proper party or parties;

          (ii) any direction or act of the Guarantor contemplated by this
       Guarantee shall be sufficiently evidenced by an Officers' Certificate;

          (iii) whenever, in the administration of this Guarantee, the Guarantee
       Trustee shall deem it desirable that a matter be proved or established
       before taking, suffering or omitting any action hereunder, the Guarantee
       Trustee (unless other evidence is herein specifically prescribed) may, in
       the absence of bad faith on its part, request and conclusively rely upon
       an Officers' Certificate which, upon receipt of such request, shall be
       promptly delivered by the Guarantor;

          (iv) the Guarantee Trustee shall have no duty to see to any recording,
       filing or registration of any instrument (or any rerecording, refiling or
       registration thereof);

          (v) the Guarantee Trustee may consult with counsel, the written advice
       or opinion of such counsel with respect legal matters shall be full and
       complete authorization and protection in respect of any action taken,
       suffered or omitted by it hereunder in good faith and in accordance with
       such advice or opinion. Such counsel may be counsel to the Guarantor or
       any of its Affiliates and may include any of its employees. The Guarantee
       Trustee shall have the right at any time to seek instructions concerning
       the administration of this Guarantee from any court of competent
       jurisdiction;

          (vi) the Guarantee Trustee shall be under no obligation to exercise
       any of the rights or powers vested in it by this Guarantee at the request
       or direction of any Holder,


                                       8

<PAGE>   13

       unless such Holder shall have provided to the Guarantee Trustee such
       security and indemnity, reasonably satisfactory to the Guarantee Trustee,
       against the costs, expenses (including attorneys' fees and expenses and
       the expenses of the Guarantee Trustee's agents, nominees or custodians)
       and liabilities that might be incurred by it in complying with such
       request or direction, including such reasonable advances as may be
       requested by the Guarantee Trustee; provided that, nothing contained in
       this Section 3.2(a)(vi) shall be taken to relieve the Guarantee Trustee,
       upon the occurrence of an Event of Default, of its obligation to exercise
       the rights and powers vested in it by this Guarantee;

          (vii) the Guarantee Trustee shall not be bound to make any
       investigation into the facts or matters stated in any resolution,
       certificate, statement, instrument, opinion, report, notice, request,
       direction, consent, order, bond, debenture, note, other evidence of
       indebtedness or other paper or document, but the Guarantee Trustee, in
       its discretion, may make such further inquiry or investigation into such
       facts or matters as it may see fit;

          (viii) the Guarantee Trustee may execute any of the trusts or powers
       hereunder or perform any duties hereunder either directly or by or
       through agents, nominees, custodians or attorneys, and the Guarantee
       Trustee shall not be responsible for any misconduct or negligence on the
       part of any agent or attorney appointed with due care by it hereunder;

          (ix) any action taken by the Guarantee Trustee or its agents hereunder
       shall bind the Holders of the Trust Preferred Securities, and the
       signature of the Guarantee Trustee or its agents alone shall be
       sufficient and effective to perform any such action. No third party shall
       be required to inquire as to the authority of the Guarantee Trustee to so
       act or as to its compliance with any of the terms and provisions of this
       Guarantee, both of which shall be conclusively evidenced by the Guarantee
       Trustee's or its agent's taking such action;

          (x) whenever in the administration of this Guarantee the Guarantee
       Trustee shall deem it desirable to receive instructions with respect to
       enforcing any remedy or right or taking any other action hereunder, the
       Guarantee Trustee (i) may request instructions from the Holders of a
       Majority in Liquidation Amount of the Trust Preferred Securities, (ii)
       may refrain from enforcing such remedy or right or taking such other
       action until such instructions are received, and (iii) shall be protected
       in conclusively relying on or acting in accordance with such
       instructions.

       (b) No provision of this Guarantee shall be deemed to impose any duty or
obligation on the Guarantee Trustee to perform any act or acts or exercise any
right, power, duty or obligation conferred or imposed on it in any jurisdiction
in which it shall be illegal, or in which the Guarantee Trustee shall be
unqualified or incompetent in accordance with applicable law, to perform any
such act or acts or to exercise any such right, power, duty or obligation. No
permissive power or authority available to the Guarantee Trustee shall be
construed to be a duty.


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<PAGE>   14

SECTION 3.3 NOT RESPONSIBLE FOR RECITALS OR ISSUANCE OF GUARANTEE.

       The Recitals contained in this Guarantee shall be taken as the statements
of the Guarantor, and the Guarantee Trustee does not assume any responsibility
for their correctness. The Guarantee Trustee makes no representation as to the
validity or sufficiency of this Guarantee.

                                  ARTICLE IV.

                                GUARANTEE TRUSTEE

SECTION 4.1 GUARANTEE TRUSTEE; ELIGIBILITY.

       (a) There shall at all times be a Guarantee Trustee which shall:

          (i) not be an Affiliate of the Guarantor; and

          (ii) be a corporation organized and doing business under the laws of
       the United States of America or any State or Territory thereof or of the
       District of Columbia, or a corporation or Person permitted by the
       Securities and Exchange Commission to act as an institutional trustee
       under the Trust Indenture Act, authorized under such laws to exercise
       corporate trust powers, having a combined capital and surplus of at least
       50 million U.S. dollars ($50,000,000), and subject to supervision or
       examination by federal, state, territorial or District of Columbia
       authority. If such corporation publishes reports of condition at least
       annually, pursuant to law or to the requirements of the supervising or
       examining authority referred to above, then, for the purposes of this
       Section 4.1(a)(ii), the combined capital and surplus of such corporation
       shall be deemed to be its combined capital and surplus as set forth in
       its most recent report of condition so published.

       (b) If at any time the Guarantee Trustee shall cease to be eligible to so
act under Section 4.1(a), the Guarantee Trustee shall immediately resign in the
manner and with the effect set out in Section 4.2(c).

       (c) If the Guarantee Trustee has or shall acquire any "conflicting
interest" within the meaning of Section 310(b) of the Trust Indenture Act, the
Guarantee Trustee and Guarantor shall in all respects comply with the provisions
of Section 310(b) of the Trust Indenture Act.

SECTION 4.2 APPOINTMENT, REMOVAL AND RESIGNATION OF GUARANTEE TRUSTEES.

       (a) Subject to Section 4.2(b), the Guarantee Trustee may be appointed or
removed without cause at any time by the Guarantor.

       (b) The Guarantee Trustee shall not be removed in accordance with Section
4.2(a) until a Successor Guarantee Trustee has been appointed and has accepted
such appointment by written instrument executed by such Successor Guarantee
Trustee and delivered to the Guarantor.

       (c) The Guarantee Trustee appointed to office shall hold office until a
Successor Guarantee Trustee shall have been appointed or until its removal or
resignation. The Guarantee


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<PAGE>   15

Trustee may resign from office (without need for prior or subsequent accounting)
by an instrument in writing executed by the Guarantee Trustee and delivered to
the Guarantor, which resignation shall not take effect until a Successor
Guarantee Trustee has been appointed and has accepted such appointment by
instrument in writing executed by such Successor Guarantee Trustee and delivered
to the Guarantor and the resigning Guarantee Trustee.

       (d) If no Successor Guarantee Trustee shall have been appointed and
accepted appointment as provided in this Section 4.2 within 60 days after
delivery to the Guarantor of an instrument of resignation, the resigning
Guarantee Trustee may petition any court of competent jurisdiction for
appointment of a Successor Guarantee Trustee. Such court may thereupon, after
prescribing such notice, if any, as it may deem proper, appoint a Successor
Guarantee Trustee.

       (e) No Guarantee Trustee shall be liable for the acts or omissions to act
of any Successor Guarantee Trustee.

       (f) Upon termination of this Guarantee or removal or resignation of the
Guarantee Trustee pursuant to this Section 4.2, the Guarantor shall pay to the
Guarantee Trustee all amounts accrued to the date of such termination, removal
or resignation.

                                   ARTICLE V.

                                    GUARANTEE

SECTION 5.1 GUARANTEE.

       The Guarantor irrevocably and unconditionally agrees to pay in full to
the Holders the Guarantee Payments (without duplication of amounts theretofore
paid by the Trust), as and when due, regardless of any defense, right of set-off
or counterclaim that the Trust may have or assert. The Guarantor's obligation to
make a Guarantee Payment may be satisfied by direct payment of the required
amounts by the Guarantor to the Holders or by causing the Trust to pay such
amounts to the Holders.

SECTION 5.2 WAIVER OF NOTICE AND DEMAND.

       The Guarantor hereby waives notice of acceptance of this Guarantee and of
any liability to which it applies or may apply, presentment, demand for payment,
any right to require a proceeding first against the Trust or any other Person
before proceeding against the Guarantor, protest, notice of nonpayment, notice
of dishonor, notice of redemption and all other notices and demands.

SECTION 5.3 OBLIGATIONS NOT AFFECTED.

       The obligations, covenants, agreements and duties of the Guarantor under
this Guarantee shall in no way be affected or impaired by reason of the
happening from time to time of any of the following:


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<PAGE>   16

       (a) the release or waiver, by operation of law or otherwise, of the
performance or observance by the Trust of any express or implied agreement,
covenant, term or condition relating to the Trust Preferred Securities to be
performed or observed by the Trust;

       (b) the extension of time for the payment by the Trust of all or any
portion of the Distributions, Redemption Price, Liquidation Distribution or any
other sums payable under the terms of the Trust Preferred Securities or the
extension of time for the performance of any other obligation under, arising out
of, or in connection with, the Trust Preferred Securities (other than an
extension of time for payment of Distributions, Redemption Price, Liquidation
Distribution or other sum payable that results from the extension of any
interest payment period on the Debentures);

       (c) any failure, omission, delay or lack of diligence on the part of the
Holders to enforce, assert or exercise any right, privilege, power or remedy
conferred on the Holders pursuant to the terms of the Trust Preferred
Securities, or any action on the part of the Trust granting indulgence or
extension of any kind;

       (d) the voluntary or involuntary liquidation, dissolution, sale of any
collateral, receivership, insolvency, bankruptcy, assignment for the benefit of
creditors, reorganization, arrangement, composition or readjustment of debt of,
or other similar proceedings affecting, the Trust or any of the assets of the
Trust;

       (e) any invalidity of, or defect or deficiency in, the Trust Preferred
Securities;

       (f) any failure or omission to receive any regulatory approval or consent
required in connection with the Trust Preferred Securities (or the common equity
securities issued by the Trust), including the failure to receive any approval
of the Board of Governors of the Federal Reserve System required for the
redemption of the Trust Preferred Securities;

       (g) the settlement or compromise of any obligation guaranteed hereby or
hereby incurred; or

       (h) any other circumstance whatsoever that might otherwise constitute a
legal or equitable discharge or defense of a guarantor, it being the intent of
this Section 5.3 that the obligations of the Guarantor hereunder shall be
absolute and unconditional under any and all circumstances.

       There shall be no obligation of the Holders to give notice to, or obtain
consent of, the Guarantor with respect to the happening of any of the foregoing.

SECTION 5.4 RIGHTS OF HOLDERS.

       (a) Subject to Section 5.4(b), the Holders of a Majority in Liquidation
Amount of the Trust Preferred Securities have the right to direct the time,
method and place of conducting of any proceeding for any remedy available to the
Guarantee Trustee in respect of this Guarantee or exercising any trust or power
conferred upon the Guarantee Trustee under this Guarantee.


                                       12

<PAGE>   17

       (b) Any Holder of Trust Preferred Securities may institute and prosecute
a legal proceeding directly against the Guarantor to enforce its rights under
this Guarantee without first instituting a legal proceeding against the Trust,
the Guarantee Trustee or any other Person. The Guarantor waives any right or
remedy to require that any action be brought first against the Trust or any
other Person before proceeding directly against the Guarantor.

SECTION 5.5 GUARANTEE OF PAYMENT.

       This Guarantee creates a guarantee of payment and not of collection.

SECTION 5.6 SUBROGATION.

       The Guarantor shall be subrogated to all (if any) rights of the Holders
of Trust Preferred Securities against the Trust in respect of any amounts paid
to such Holders by the Guarantor under this Guarantee; provided however, that
the Guarantor shall not (except to the extent required by mandatory provisions
of law) be entitled to enforce or exercise any right that it may acquire by way
of subrogation or any indemnity, reimbursement or other agreement, in all cases
as a result of payment under this Guarantee, if, at the time of any such
payment, any amounts are due and unpaid under this Guarantee. If any amount
shall be paid to the Guarantor in violation of the preceding sentence, the
Guarantor agrees to hold such amount in trust for the Holders and to pay over
such amount to the Holders.

SECTION 5.7 INDEPENDENT OBLIGATIONS.

       The Guarantor acknowledges that its obligations hereunder are independent
of the obligations of the Trust with respect to the Trust Preferred Securities,
and that the Guarantor shall be liable as principal and as debtor hereunder to
make Guarantee Payments pursuant to the terms of this Guarantee notwithstanding
the occurrence of any event referred to in subsections (a) through (h),
inclusive, of Section 5.3 hereof.

                                  ARTICLE VI.

                    LIMITATION OF TRANSACTIONS; SUBORDINATION

SECTION 6.1 LIMITATION OF TRANSACTIONS.

       So long as any Trust Preferred Securities remain Outstanding, if there
shall have occurred an Event of Default under this Guarantee, an event of
default under the Indenture, an event of default under the Trust Agreement or
during an Extended Interest Payment Period (as defined in the Indenture), then
(a) the Guarantor shall not and will not permit any Subsidiary to declare or pay
any dividend on, make any distributions with respect to, or redeem, purchase,
acquire or make a liquidation payment with respect to, any of its capital stock
(other than (I) dividends or distributions in common stock of the Guarantor or
such Subsidiary, as the case may be, or any declaration of a non-cash dividend
in connection with the implementation of a shareholder rights plan, or the
issuance of stock under any plan in the future, or the redemption or repurchase
of any such rights pursuant thereto, (II) purchases of common stock of the
Guarantor related to the rights under any of the Guarantor's benefit plans for
its directors, officers or employees, (III) as a result of a reclassification of
its capital stock for another class of its capital stock, or (IV) declarations
or


                                       13

<PAGE>   18

payments of dividends or distributions on capital stock by a Subsidiary of the
Guarantor to the Guarantor or any of its Subsidiaries; (b) the Guarantor shall
not and will not permit any Subsidiary to make any payment of interest,
principal or premium, if any, on or repay, repurchase or redeem any debt
securities issued by the Guarantor which rank pari passu with or junior to the
Debentures or make any Guarantee Payments with respect to debt securities of any
Subsidiary of the Guarantor that rank pari passu with or junior to the
Debentures; provided, however, that notwithstanding the foregoing the Guarantor
may make payments pursuant to its obligations under this Guarantee; and (c) the
Guarantor shall not redeem, purchase or acquire less than all of the outstanding
Debentures or any of the Trust Preferred Securities.

SECTION 6.2 RANKING.

       This Guarantee will constitute an unsecured obligation of the Guarantor
and will rank (i) subordinate and junior in right of payment to all Senior Debt,
Subordinated Debt and Additional Senior Obligations, as defined in the
Indenture, of the Guarantor, to the extent and in the manner set forth in the
Indenture, and the applicable provisions of the Indenture will apply, in all
relevant respects, to the obligations of the Guarantor hereunder and (ii) senior
to the Guarantor's capital stock.

                                  ARTICLE VII.

                                   TERMINATION

SECTION 7.1 TERMINATION.

       This Guarantee shall terminate upon (i) full payment of the Redemption
Price of all Trust Preferred Securities, (ii) upon full payment of the amounts
payable in accordance with the Trust Agreement upon liquidation of the Trust, or
(iii) upon distribution of the Debentures to the Holders of the Trust Preferred
Securities. Notwithstanding the foregoing, this Guarantee shall continue to be
effective or shall be reinstated, as the case may be, if at any time any Holder
of Trust Preferred Securities must restore payment of any sums paid under the
Trust Preferred Securities or under this Guarantee.

                                 ARTICLE VIII.

                                INDEMNIFICATION

SECTION 8.1 EXCULPATION.

       (a) No Indemnified Person shall be liable, responsible or accountable in
damages or otherwise to the Guarantor or any Covered Person for any loss, damage
or claim incurred by reason of any act or omission performed or omitted by such
Indemnified Person in good faith in accordance with this Guarantee and in a
manner that such Indemnified Person reasonably believed to be within the scope
of the authority conferred on such Indemnified Person by this Guarantee or by
law, except that an Indemnified Person shall be liable for any such loss, damage
or claim incurred by reason of such Indemnified Person's negligence or willful
misconduct with respect to such acts or omissions.


                                       14
<PAGE>   19

       (b) An Indemnified Person shall be fully protected in relying in good
faith upon the records of the Guarantor and upon such information, opinions,
reports or statements presented to the Guarantor by any Person as to matters the
Indemnified Person reasonably believes are within such other Person's
professional or expert competence and who has been selected with reasonable care
by or on behalf of the Guarantor, including information, opinions, reports or
statements as to the value and amount of the assets, liabilities, profits,
losses, or any other facts pertinent to the existence and amount of assets from
which Distributions to Holders of Trust Preferred Securities might properly be
paid.

SECTION 8.2 INDEMNIFICATION.

       The Guarantor agrees to indemnify each Indemnified Person for, and to
hold each Indemnified Person harmless against, any loss, liability or expense
incurred without negligence or bad faith on its part, arising out of or in
connection with the acceptance or administration of the trust or trusts
hereunder, including the costs and expenses (including reasonable legal fees and
expenses) of defending itself against, or investigating, any claim or liability
in connection with the exercise or performance of any of its powers or duties
hereunder. The obligation to indemnify as set forth in this Section 8.2 shall
survive the termination of this Guarantee.

       When the Guarantee Trustee incurs expenses or renders services in
connection with an Event of Default specified in Section 7.1(a)(iv) or (v) of
the Indenture, the expenses including the reasonable charges and expenses of its
counsel) and the compensation for services are intended to constitute expenses
of administration under any applicable federal or state bankruptcy, insolvency
or other similar law.

                                  ARTICLE IX.

                                 MISCELLANEOUS

SECTION 9.1 SUCCESSORS AND ASSIGNS.

       All guarantees and agreements contained in this Guarantee shall bind the
successors, assigns, receivers, trustees and representatives of the Guarantor
and shall inure to the benefit of the Holders of the Trust Preferred Securities
then outstanding. Except in connection with any merger or consolidation of the
Guarantor with or into another entity permitted by Section 12.1 of the Indenture
or any sale, transfer, conveyance or other disposition of the property of the
Guarantor permitted by Section 12.1 of the Indenture, the Guarantor may not
assign its rights or delegate its obligations under this Guarantee.

SECTION 9.2 AMENDMENTS.

       Except with respect to any changes that do not materially adversely
affect the rights of Holders (in which case no consent of Holders will be
required), this Guarantee may only be amended with the prior approval of the
Holders of at least a Majority in Liquidation Amount of the Trust Preferred
Securities. The provisions of Article VI of the Trust Agreement with respect to
meetings of Holders of the Trust Preferred Securities apply to the giving of
such approval.


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<PAGE>   20

SECTION 9.3 NOTICES.

       All notices provided for in this Guarantee shall be in writing, duly
signed by the party giving such notice, and shall be delivered, telecopied or
mailed by registered or certified mail, as follows:

       (a) If given to the Guarantee Trustee, at the Guarantee Trustee's mailing
address set forth below (or such other address as the Guarantee Trustee may give
notice of to the Holders of the Trust Preferred Securities):

               Wilmington Trust Company
               Rodney Square North
               1100 North Market Street
               Wilmington, Delaware 19890-0001
               Attention:  Corporate Trust Administration

       (b) If given to the Guarantor, at the Guarantor's mailing address set
forth below (or such other address as the Guarantor may give notice of to the
Holders of the Trust Preferred Securities):

               Glacier Bancorp, Inc.
               48 Commons Loop
               Kalispell, Montana 59901
               Attention: Michael J. Blodnick, President and Chief Executive
                          Officer

       (c) If given to any Holder of Trust Preferred Securities, at the address
set forth on the books and records of the Trust. All such notices shall be
deemed to have been given when received in person, telecopied with receipt
confirmed, or mailed by first class mail, postage prepaid except that if a
notice or other document is refused delivery or cannot be delivered because of a
changed address of which no notice was given, such notice or other document
shall be deemed to have been delivered on the date of such refusal or inability
to deliver.

SECTION 9.4 BENEFIT.

       This Guarantee is solely for the benefit of the Holders of the Trust
Preferred Securities and, subject to Section 3.1(a), is not separately
transferable from the Trust Preferred Securities.

SECTION 9.5 GOVERNING LAW.

THIS GUARANTEE SHALL BE GOVERNED BY, AND CONSTRUED AND INTERPRETED IN ACCORDANCE
WITH, THE LAWS OF THE STATE OF DELAWARE (WITHOUT REGARD TO CONFLICT OF LAWS
PRINCIPLES).

This Guarantee is executed as of the day and year first above written.

                                  GLACIER BANCORP, INC., as Guarantor

                                  By:
                                        ----------------------------------------


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<PAGE>   21

                                  Its:
                                         ---------------------------------------

                                  WILMINGTON TRUST COMPANY, as Guarantee Trustee

                                  By:
                                        ----------------------------------------

                                  Its:
                                         ---------------------------------------

                                       17