Executive Employment Agreement
EFFECTIVE DATE:
This Executive Employment Agreement (this “Agreement”) is dated as of September
23, 2015

(the “Effective Date”)

PARTIES:
First Interstate BancSystem, Inc.

P.O. Box 30918
401 North 31st Street
Billings MT 59116-0918
(“Employer”)

Kevin P. Riley
3131 Iron Horse Trail #21
Billings MT 59106
(“Executive”)
Recitals
A.Employer is a financial services holding company, headquartered in Billings,
Montana, and is the parent company of First Interstate Bank, a community bank
with offices throughout Montana, Wyoming, and South Dakota.

B.Executive has nearly 30 years of experience in various positions in the
financial services industry, most recently as Chief Financial Officer of
Employer.

C.Employer has extended an offer of employment to Executive to serve as its
President and Chief Executive Officer subject to the terms and conditions set
forth in this Agreement. Executive accepts employment on the terms, covenants,
and conditions set forth in this Agreement.
Agreement
In consideration of the foregoing recitals and the covenants and promises
contained in this Agreement, and for other good and valuable consideration, the
receipt and sufficiency of which are acknowledged, Employer and Executive agree
as follows:
Article I.
DEFINITIONS AND INTERPRETATIONS

1.1Definitions. In addition to the terms defined elsewhere in this Agreement, as
used in this Agreement, the following terms have the following meanings:

“Board” means the Board of Directors of Employer.

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“Cause” means (1) any gross misconduct, negligence, or omission by Executive;
(2) Executive’s material failure or refusal to adhere to the terms of this
Agreement or to Employer’s written policies, rules and practices applicable to
Executive; (3) Executive’s insubordination or failure to follow Board
directives; (4) Executive’s unauthorized disclosure of Confidential Information
(defined below) or breach of the Confidentiality provisions contained herein;
(5) a material act or acts of dishonesty by Executive involving Employer;
(6) Executive’s willful misconduct damaging the Employer, its reputation,
products, services, or customers; or (7) commission by Executive of a criminal
offense that, if committed in the State of Montana, would have constituted a
felony under the laws of the State of Montana or the United States.
“Disability” means any mental or physical condition as a result of which
Executive is unable or fails to perform the duties required of Executive under
this Agreement, with or without an accommodation, for a period of at least 90
days (which need not be consecutive) during any 12 month period. During any
period of Disability Executive must exhaust available PTO and short-term
disability.
“Good Reason” means a special right of Executive to terminate employment at his
initiative within 90 days following the occurrence of one or more of the
following events (except as a result of a prior termination, and except for such
events that occur with Executive’s written consent), provided that Executive has
provided Employer with notice of such event within 30 days of its initial
existence and Employer has not remedied such condition within 30 days of such
notice:
(a)a material diminution or change, adverse to Executive, in Executive’s
positions, titles, status, rank, nature of responsibilities, or authority with
Employer (for this purpose, Executive’s removal as a member of Employer’s Board
will only constitute Good Reason if Executive is not nominated for re-election
by the Board);

(b)a material decrease in Executive’s annual Base Salary, or a decrease in the
target bonus award opportunities described in Article V of this Agreement (other
than an across-the-board reduction on a percentage basis for all Named Executive
Officers);

(c)a material reduction in the aggregate benefits for which Executive is
eligible under Employer’s benefit plans (other than an across-the-board
reduction in the aggregate benefits for all Named Executive Officers); or

(d)Employer requiring Executive to relocate more than 50 miles outside of
Billings, Montana.

“Named Executive Officers” means those persons designated as named executive
officers, or NEOs, in Employer’s definitive proxy statement most recently filed
with the Securities and Exchange Commission under cover of Schedule 14A
promulgated under the Securities Exchange Act of 1934, as amended, or as any
such proxy statement is amended by subsequent filing.
1.2    Interpretation. Unless a clear contrary intention appears, as used in
this Agreement (a) the singular includes the plural and vice versa,
(b) reference to any document means such document as amended from time to time,
(c) “include” and “including” means

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including without limiting the generality of any description preceding such
term, (d) the word “or” is not exclusive, unless otherwise expressly stated,
(e) the terms “hereof,” “herein,” “hereby,” and derivative or similar words
refer to this entire Agreement, and (f) headings are for convenience only and do
not constitute a part of this Agreement.

Article II.
EMPLOYEMENT DUTIES

Employer will employ Executive as its President and Chief Executive Officer for
Employer, and Executive will reside and maintain his principal office in
Billings, Montana, and accepts employment under the terms and conditions set
forth in this Agreement. Executive will be responsible for performing the
business and professional services typically performed by the President and
Chief Executive Officer of any company, or as may reasonably be assigned to him
by the Board, subject to the general and customary supervision by the Board.
Article III.
FULL-TIME BEST EFFORTS

2.1Full-Time Best Efforts. Executive agrees to devote the professional time and
attention required to perform Executive’s obligations under this Agreement, and
agrees at all times faithfully, industriously and to the best of Executive’s
ability, experience and talent to perform all of Executive’s obligations under
this Agreement. Until this Agreement is terminated, Executive may not be
employed or engaged by any other person or firm other than Employer unless
otherwise provided for in Employer’s policies or authorized by the Board.

3.2.No Conflicting Obligations. Executive represents and warrants to Employer
that he is under no obligation or commitment, whether contractual or otherwise,
that is inconsistent with his obligations under this Agreement. Executive
represents and warrants that he will not use or disclose, in connection with his
employment by Employer, any trade secrets or other proprietary information or
intellectual property in which Executive or any other person has any right,
title, or interest and that his employment by Employer as contemplated by this
Agreement will not infringe or violate the rights of any other person or entity.
Executive represents and warrants to Employer that he has returned all property
and confidential information belonging to any prior employers.

Article IV.
TERM AND TERMINATION

4.1    Term. The term of this Agreement will begin on the Effective Date and
continue until 11:59 p.m. on December 31, 2018 (“Employment Term”). This
Agreement may be renewed for successive one-year terms upon written agreement of
both parties no later than 60 days prior to the end of the term.

4.2Termination. Notwithstanding Section 4.1:

(a)This Agreement may be terminated by the agreement of Employer and Executive.

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(b)This Agreement and Executive’s employment will terminate immediately upon
Executive’s death.
    
(c)This Agreement may be terminated by Employer on or after the 90th day of
Executive’s Disability.
    
(d)Employer may terminate this Agreement immediately upon notice for Cause.
    
(e)Executive may terminate this Agreement upon 60 days’ written notice to
Employer with or without Good Reason.
    
(f)Upon termination of Executive’s employment under this Agreement, Employer
will have no further obligation to Executive except as specifically provided
under this Agreement or as provided for in Employer’s compensation and benefit
plans. Executive’s obligations under Article VIII and Article IX will survive
termination of this Agreement. Upon termination of this Agreement, Executive
agrees to return to Employer any and all equipment, client, project and investor
information including, without limitation, confidential files, proprietary
information, client files, investor information, project files, construction
files, electronic equipment, vehicles, keys, credit cards, and the like, owned
by Employer and used by, or in the possession of, Executive.

Article V.
COMPENSATION AND BENEFITS

5.1    Base Salary. Employer agrees to pay Executive an annual salary of Five
Hundred Twenty Five Thousand Dollars ($525,000) (the “Base Salary”) in
accordance with Employer’s regular payroll practices. This Base Salary is
subject to periodic review and adjustment.

5.2Short-Term Incentive Program. Executive will be eligible for an award under
any short-term incentive or annual bonus program offered by Employer to its
Named Executive Officers. Starting with the year commencing January 1, 2016,
Executive will be eligible to earn a bonus based on the target incentive equal
to 50% of his Base Salary (“Target Bonus”). For 2015, Executive will be eligible
to earn a maximum bonus based on the target incentive calculated as follows: (1)
40% of his base salary as Chief Financial Officer of Three Hundred Twenty One
Thousand Three Hundred Sixty Dollars ($321,360) prorated over the first nine
months of the year; and (2) 50% of his Base Salary as Chief Executive Officer
prorated over the last three months of the year.

5.3Long-Term Incentive Plan. Executive will be eligible for grants of equity and
incentive compensation under any equity or incentive compensation program
offered by Employer to its Named Executive Officers. Executive’s target
long-term incentive for the year commencing 2016 will be no less than 50% of his
Base Salary.

5.4    Promotional Grant. Executive will receive a one-time award of restricted
stock (the “Promotional Shares”) in an amount equal to the fair market value of
Three Hundred Thousand Dollars ($300,000), effective as of September 25, 2015.
The Promotional Shares will vest in equal installments on September 25 of 2016,
2017 and 2018. Any Promotional Shares not vested will be forfeited if
Executive’s employment with Employer terminates. The grant of

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the Promotional Shares will be subject to the terms of Employer’s 2015 Equity
Incentive Plan and a Restricted Stock Grant Agreement provided to Executive on
or around September 25, 2015.

5.5Nonqualified Deferred Compensation. Employer agrees to develop a nonqualified
deferred compensation program, either as part of its existing nonqualified
deferred compensation plan or through a new supplemental executive retirement
plan, pursuant to which Employer will agree to make a contribution as of the end
of each calendar year beginning with 2016. Employer’s contributions will be
contingent on Executive’s employment with Employer as of the last day of the
calendar year, and will be subject to vesting and other terms to be negotiated.
The amount of Employer’s contribution on Executive’s behalf will equal 20% of
Executive’s Base Salary, plus an additional contribution of up to an additional
20% of Executive’s Base Salary contingent on performance criteria.

5.6Business Expenses. Employer will reimburse Executive for any business-related
expenses approved pursuant to Employer’s policy.

5.7Fringe Benefits. Executive will be entitled to participate in any plans,
arrangements or distributions by Employer pertaining to or in connection with
any leave, paid time off (“PTO”) health insurance, pension, 401(k) and profit
sharing plans or benefits that Employer adopts for the senior management
executives of Employer (the “Fringe Benefits”) on terms no less favorable than
provided to other Named Executive Officers. Executive will be subject to all of
the rules of Employer’s plans providing the Fringe Benefits, including without
limitation, rules regarding participation and vesting.

5.8Company Car and Social Club Membership. Employer will purchase a company
vehicle for Executive to use. The purchase price of the car shall not exceed
$65,000. Employer will provide to Executive a membership to one of the country
clubs in Billings, Montana.
Article VI.
SEVERANCE PAYMENTS AND BENEFITS
6.1    Employer’s Termination of Executive for Cause or Executive’s Resignation
without Good Reason. In the event that Employer terminates Executive’s
employment for Cause or Executive resigns without Good Reason, Employer agrees
to pay Executive any accrued but unpaid Base Salary through the date of
termination or resignation, all accrued but unused PTO earned through the date
of termination or resignation, and any reimbursement of expenses owed pursuant
to this Agreement on Employer’s next regularly scheduled pay day.

6.2Termination due to Executive’s Death or Disability. In the event that
Executive’s employment terminates for death or Disability, Employer agrees to
pay Executive or his estate:
(a)all accrued but unpaid Base Salary through the date of termination, paid on
Employer’s next regularly scheduled pay day after termination;

(b)all accrued but unused PTO earned through the date of termination, paid on
Employer’s next regularly scheduled pay day after termination;

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(c)any reimbursement of expenses owed pursuant to this Agreement, paid on
Employer’s next regularly scheduled pay day after the expenses have been
approved; and

(d)any benefit Executive or his estate may be entitled to under any life or
disability plan provided by Employer.

6.3Executive’s Resignation for Good Reason. In the event that Executive resigns
for Good Reason (other than in connection with a Change in Control where
Executive would be entitled to benefits under Section 6.4 of this Agreement and
shall not be entitled to any severance benefits under this Section 6.3),
Employer agrees to pay Executive the following severance benefits:

(a)all accrued but unpaid Base Salary through the date of termination or
resignation, paid on Employer’s next regularly scheduled pay day after
termination or resignation;

(b)all accrued but unused PTO earned through the date of termination or
resignation, paid on Employer’s next regularly scheduled pay day after
termination or resignation;

(c)any reimbursement of expenses owed pursuant to this Agreement, paid on
Employer’s next regularly scheduled pay day after the expenses have been
approved;

(d)an amount equal to 1.5 times the Base Salary in effect at the time of the
resignation, which shall be paid to Executive in 18 monthly installments
commencing on the 60th day after the termination date (subject, however, to
delay if applicable under Section 11.11 of this Agreement); and

(e)an additional monthly amount equal to the full premium cost for Executive to
continue any applicable medical, health, or life insurance as in effect
immediately prior to the date of termination, for a period not to exceed 18
months and terminating on any earlier date on which Executive becomes eligible
for coverage from a subsequent employer. In the event such benefit would (in
Employer’s determination) violate the non-discrimination rules applicable to
group medical plans under the Patient Protection and Affordable Care Act of
2010, Internal Revenue Code Section 105(h), or other applicable law, Employer
will treat such amounts as taxable income with respect to Executive and
Executive will be responsible for all applicable taxes and withholdings.

6.4Termination following Change in Control. In the event that Employer
terminates Executive (other than for Cause, Death or Disability) during the
24-month period following or the 6-month period preceding a Change in Control
(as such term is defined in Employer’s 2015 Equity and Incentive Plan), or in
the event that Executive resigns for Good Reason during such 30-month period,
Employer agrees to pay Executive the following severance benefits:

(a)all accrued but unpaid Base Salary through the date of termination or
resignation, paid on Employer’s next regularly scheduled pay day after
termination or resignation;

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(b)all accrued but unused PTO earned through the date of termination or
resignation, paid on Employer’s next regularly scheduled pay day after
termination or resignation;

(c)any reimbursement of expenses owed pursuant to this Agreement, paid on
Employer’s next regularly scheduled pay day after the expenses have been
approved;

(d)an amount equal to 1.5 times the Base Salary plus Target Bonus in effect at
the time of the resignation or in effect immediately preceding the Change in
Control, whichever is higher, which shall be paid to Executive in 18 monthly
installments commencing on the 60th day after the termination date (or, if
later, 60 days after the Change in Control is effective, and subject to delay if
applicable under Section 11.11 of this Agreement);

(e)a pro rata portion of the Executive’s Target Bonus for the calendar year of
the termination, less applicable withholdings and deductions, paid in a lump sum
no later than 60 days after the termination date (or, if later, 60 days after
the Change in Control is effective, and subject to delay if applicable under
Section 11.11 of this Agreement); and

(f)an additional monthly amount equal to the full premium cost for Executive to
continue any applicable medical, health, or life insurance as in effect
immediately prior to the date of termination, for a period not to exceed 18
months and terminating on any earlier date on which Executive becomes eligible
for coverage from a subsequent employer. In the event such benefit would (in
Employer’s determination) violate the non-discrimination rules applicable to
group medical plans under the Patient Protection and Affordable Care Act of
2010, Internal Revenue Code Section 105(h), or other applicable law, Employer
will treat such amounts as taxable income with respect to Executive and
Executive will be responsible for all applicable taxes and withholdings.

6.5Conditions To Payment of Severance.

(a)Notwithstanding anything to the contrary contained in this Agreement, to the
extent that any of the payments and benefits provided for under this Agreement
or any other agreement or arrangement between Employer and Executive
(collectively, the “Payments”) (i) constitute a “parachute payment” within the
meaning of Internal Revenue Code Section 280G and (ii) but for this paragraph
would be subject to the excise tax imposed by Code Section 4999, then the
Payments shall be payable either (a) in full or (b) as to such lesser amount
which would result in no portion of such Payments being subject to excise tax
under Code Section 4999, whichever of the foregoing amounts, taking into account
the applicable federal, state and local income taxes and the excise tax imposed
by Section 4999, results in Executive’s receipt on an after-tax basis of the
greatest amount of benefits under this Agreement, notwithstanding that all or
some portion of such benefits may be taxable under Section 4999. Unless
Executive and Employer otherwise agree in writing, any determination required
under this paragraph will be made in writing by Employer’s independent public
accountants, whose determination shall be conclusive and binding upon Executive
and Employer for all purposes. Any reduction may be made by Employer in its sole
discretion consistent with the requirements of Code Section 409A.

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(b)Any payments under Section 6.3 or 6.4 will be made only if, at the time
scheduled for such payment, Executive has executed (and the applicable
revocation periods have expired) a complete release in favor of Employer, its
affiliates, and all of their respective officers, directors, employees,
principals, managers, partners, members, attorneys, and representatives, in form
and substance satisfactory to Employer.

Article VII.
WITHHOLDING TAX
Employer is entitled to withhold from the Base Salary and any other amounts that
it pays to Executive under this Agreement or otherwise, an amount sufficient to
satisfy all federal, state and local income and employment tax withholding
requirements with respect to any and all amounts paid to Executive by Employer.
Article VIII.
CONFIDENTIAL INFORMATION

8.1Confidential Information. “Confidential Information” as used in this
Agreement means any and all communications, information, records, documents,
material, data or ideas regarding Employer, including, without limitation, lists
of customers; names, addresses, electronic mail addresses and telephone numbers
of customers; customer account information; lists of expiration dates of
insurance policies sold to customers; financial models and spreadsheets; project
development plans and specifications; partnership agreements and legal
documents; corporate information and proprietary data as well as future
development plans; and any communication with investors, prospective investors,
partners, developers, architects, engineers, contractors, lenders, consultants
or any other service providers. Information disclosed to Executive by Employer
or learned by Executive in the course of Executive’s employment with Employer
will be considered Confidential Information by Executive unless the information
is conspicuously designated as “Not Confidential” or, if provided orally,
identified as not confidential at the time of disclosure.

8.2Nondisclosure and Nonuse Obligation. Executive may not disseminate or in any
way disclose any Confidential Information to any person, agency, department,
firm or business, provided, Executive may disclose Confidential Information to
other employees of Employer, including, without limitation, officers,
accountants, attorneys, and directors of Employer. Notwithstanding any other
provision of this Agreement, this Agreement will not apply to any Confidential
Information: (i) to the extent disclosure is required by law or is necessary to
establish the rights of either party to this Agreement; (ii) disclosure of which
is authorized in writing by Employer; or (iii) that is in the public domain or
becomes part of the public domain through no violation of this Agreement.
Executive must promptly give notice to Employer of any unauthorized use or
disclosure of any Confidential Information. Employee agrees to assist Employer
in remedying any unauthorized use or disclosure of any Confidential Information.
Nothing herein shall prevent Executive from disclosing Confidential Information
that impacts his personal financial situation to his financial advisors,
accountants or attorneys.

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Article IX.
COMPETITION AND NON-SOLICITATION

9.1Competition. From and after the termination of Executive’s employment with
Employer (the “Termination Date”) until eighteen months after the Termination
Date (the “Restricted Period”), Executive may compete with Employer and own,
operate, manage, control, engage in, participate in, invest in, hold any
interest in, assist, aid, act as a consultant to or otherwise advise in any way,
be employed by or perform any services (alone or in association with any person)
for, any person (or on behalf of Executive) that engages in or owns, invests in,
operates, manages or controls any venture or enterprise that directly competes
with Employer upon prior written approval of the Board. However, if Executive,
without the prior written approval of the Board, competes with Employer or owns,
operates, manages, controls, engages in, participates in, invests in, holds any
interest in, assists, aids, acts as a consultant to or otherwise advises in any
way, is employed by or performs any services (alone or in association with any
person) for any person (or on behalf of Executive) that engages in or owns,
invests in, operates, manages or controls any venture or enterprise that
directly competes with Employer at any time during the Restricted Period,
Executive agrees to forfeit any future severance benefits and return to Employer
any severance benefits already paid pursuant to Section 6.3 or 6.4 of this
Agreement. Nothing in this Agreement shall prevent the Executive from passive
investments of less than 1% in public companies or indirect investments through
401(k) plans, mutual funds, etc.

9.2Non-Solicitation. Executive agrees that during the Restricted Period he will
not, except on behalf of Employer or with the express written permission of
Employer, which may be given or withheld in Employer’s sole discretion, directly
or indirectly solicit, or attempt to solicit (on Executive’s own behalf or on
behalf of any other person or entity) any customers of Employer or its
affiliates, or the employment or retaining of any employee or consultant of
Employer or its affiliates.

Article X.
ARBITRATION

Any dispute arising out of or relating to this Agreement shall be settled or
made by binding arbitration at a location in Billings, Montana pursuant to the
Montana Uniform Arbitration Act or other applicable Montana law, and where not
inconsistent, in accordance with the Commercial Arbitration Rules of the
American Arbitration Association now or hereafter in effect. The parties to the
dispute shall unanimously select the arbitrator. In the event the parties to the
dispute are unable to unanimously select an arbitrator within ten (10) days of
notice from any party to the dispute to all other parties to the dispute of the
need to select an arbitrator, the arbitrator shall be selected in accordance
with the Montana Uniform Arbitration Act. The parties to the dispute shall
confer with the arbitrator and together shall decide upon a time and date for
the arbitration hearing. If the parties to the dispute and the arbitrator are
unable to agree upon a time and date for the arbitration hearing, the arbitrator
shall determine the time and date for the arbitration hearing. The parties to
the dispute shall equally split the arbitrator’s fees and costs. In agreeing to
the method of dispute resolution set forth in this arbitration clause, the
parties specifically acknowledge that each prefers to resolve disputes by
arbitration rather than through

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the formal court process. FURTHER, EACH OF THEM UNDERSTANDS THAT BY AGREEING TO
ARBITRATIONS EACH OF THEM IS WAIVING THE RIGHT TO RESOLVE DISPUTES ARISING FROM
OR RELATING TO THIS AGREEMENT IN COURT BY A JUDGE OR JURY, THE RIGHT TO A JURY
TRIAL, THE RIGHT TO DISCOVERY AVAILABLE UNDER THE MONTANA RULES OF CIVIL
PROCEDURE, THE RIGHT TO FINDINGS OF FACT BASED ON THE EVIDENCE, AND THE RIGHT TO
ENFORCE THE LAW APPLICABLE TO ANY CASE ARISING OUT OF OR RELATING TO THIS
AGREEMENT BY WAY OF APPEAL, EXCEPT AS ALLOWED UNDER THE MONTANA UNIFORM
ARBITRATION ACT. Each of them also acknowledges that each has had an opportunity
to consider and study this arbitration provision, to consult with counsel, to
suggest modifications or changes, and, if requested, has received and reviewed a
copy of the Montana Uniform Arbitration Act.
Article XI.
MISCELLANEOUS

11.1Key-Employee Insurance. Executive agrees that Employer may, from time to
time, apply for and take out in its own name and at its own expense, life,
health, accident, or other insurance upon Executive that Employer may deem
necessary or advisable to protect its interests; and Executive agrees to submit
to any medical or other examination necessary for such purposes and to assist
and cooperate with Employer in preparing such insurance; and Executive agrees
that he will have no right, title, or interest in or to such insurance.

11.2Governing Law. This Agreement shall be governed by the laws of the State of
Montana.

11.3No Waiver. The failure of either party to demand strict performance and
compliance with any part of this Agreement shall not be deemed to be a waiver of
the rights of such party under this Agreement or by operation of law. Any waiver
by either party of a breach of any provision of this Agreement shall not operate
as or be construed as a waiver of any subsequent breach thereof.

11.4Severability. The invalidity of any provision of this Agreement or portion
of a provision shall not affect the validity of any other provision of this
Agreement or the remaining portion of the applicable provision.

11.5Counterparts and Facsimile Signatures. This Agreement and any amendments to
this Agreement may be executed in two or more counterparts, each of which shall
be deemed an original and all of which, taken together, shall constitute one
agreement. A facsimile or electronic signature to this Agreement and any
amendments to this Agreement shall be deemed an original and binding upon the
party against whom enforcement is sought.

11.6Notices. All notices required or permitted under this Agreement shall be in
writing and shall be deemed effectively given: (i) upon personal delivery to the
party to be notified; (ii) when sent by confirmed facsimile or electronic mail
if sent during normal business hours of the recipient, if not, then on the next
business day; or (iii) upon receipt, if sent by registered or certified mail or
nationally recognized overnight courier. All notices shall be sent

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to Employer or Executive at the address set forth on the first page of this
Agreement, or at such other address as either party may designate by notice
pursuant to this Section.

11.7Entire Agreement. The terms of this Agreement express and constitute the
entire agreement between the parties pertaining to the subject matter of this
Agreement and supersede all prior and contemporaneous agreements, term sheets,
offer letters, understandings, negotiations and discussions, whether oral or
written, of the parties. No supplement, modification, waiver or termination of
this Agreement shall be binding, unless executed in writing by the party to be
bound.

11.8Acknowledgments; Separate Representation. Each of the parties represents,
acknowledges and agrees that the respective party has been advised to consult
with professional legal and accounting advisors with respect to the legal and
tax consequences of the transactions described in this Agreement and all
agreements referenced in this Agreement, and each party has obtained and relied
upon its own independent legal and accounting advisors in connection with the
transactions contemplated in this Agreement.

11.9Amendment. This Agreement may be amended or altered by written instrument
executed by all of the parties to this Agreement.

11.10Attorney’s Fees. In the event of any arbitration or other proceeding for
the interpretation or enforcement of this Agreement, the prevailing party in
such arbitration or other legal proceeding shall be entitled to recover its
costs and expenses incurred, including, without limitation, reasonable
attorneys’ fees

11.11Code Section 409A. The intent of the parties is that payments and benefits
under this Agreement (including all attachments, exhibits and annexes) be exempt
from or comply with Section 409A of the Internal Revenue Code of 1986, to the
extent subject thereto, and, accordingly, to the maximum extent permitted, this
Agreement shall be interpreted and be administered to be in compliance
therewith. Notwithstanding anything contained herein to the contrary, to the
extent required in order to avoid accelerated taxation and/or tax penalties
under Code Section 409A, Executive shall not be considered to have terminated
employment with Employer for purposes of this Agreement, and no payment shall be
due to Executive under this Agreement, until Executive would be considered to
have incurred a “separation from service” from Employer within the meaning of
Code Section 409A. Each amount to be paid or benefit to be provided to Executive
pursuant to this Agreement that constitutes deferred compensation subject to
Code Section 409A shall be construed as a separate identified payment for
purposes of Code Section 409A. Notwithstanding anything to the contrary in this
Agreement, to the extent that any payments to be made to Executive upon his or
her separation from service would result in the imposition of any individual
penalty tax imposed under Code Section 409A by reason of Executive’s status as a
“specified employee,” the payment shall instead be made on the first business
day after the earlier of (i) the date that is six months following such
separation from service and (ii) Executive’s death. To the extent that the
Agreement provides for the reimbursement of specified expenses incurred by
Executive, such reimbursement shall be made in accordance with the provisions of
the Agreement, but in no event later than the last day of Executive’s taxable
year following the taxable year in which the expense was incurred. The amount of
expenses eligible for reimbursement or in-kind benefits provided by Employer in
any

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taxable year of Executive shall not affect the amount of expenses or in-kind
benefits to be reimbursed or provided in any other year (except in the case of
maximum benefits to be provided under a medical reimbursement arrangement, if
applicable).

11.12Recovery of Compensation in Connection with Financial Restatement.
Notwithstanding any other provision of this Agreement to the contrary, if the
Board determines that Employer is required to restate its financial statements
due to material noncompliance with any financial reporting requirement under the
law, whether such noncompliance is the result of misconduct or other
circumstances, Executive shall reimburse Employer for any amounts earned or
payable to the extent required by applicable law and Employer’s Clawback Policy.
Without limiting the foregoing, all compensation paid by Employer to Executive
is subject to any compensation recapture policies required by applicable law
(including the Sarbanes-Oxley Act of 2002) or that are established by Employer
from time to time, including any clawback policy adopted or implemented in
respect of the Dodd-Frank Wall Street Reform and Consumer Protection Act of 2010
and such regulations as are promulgated thereunder from time to time to the
extent required therein and the implementing regulations.

The parties have executed this Agreement effective as the Effective Date.

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EMPLOYER:

First Interstate BancSystem, Inc.

By: /s/ THOMAS W. SCOTT    
Thomas W. Scott
Chairman of the Board of Directors
Date: September 25, 2015
      

EXECUTIVE:

/s/ KEVIN P. RILEY    
Kevin P. Riley
Date: September 25, 2015

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