Document:

Exhibit 10.1

 

[●], 2021

 

Mount Rainier Acquisition Corp

256 W. 38th Street, 15th Floor

New York, NY 10018

 

A.G.P./ Alliance Global Partners

590 Madison Avenue, 28th Floor

New York, NY 10022

 

Re: Initial Public Offering

 

Ladies and Gentlemen:

 

This letter (this “Letter Agreement”)
is being delivered to you in accordance with the Underwriting Agreement (the “Underwriting Agreement”) entered
into by and among Mount Rainier Acquisition Corp., a Delaware corporation (the “Company”), and A.G.P./Alliance
Global Partners, as representative (the “Representative”), of the several underwriters (each an “Underwriter”
and collectively, the “Underwriters”), relating to an underwritten initial public offering (the
 “Public Offering”), of 15,000,000 of the Company’s units (including up to 2,250,000 units that may be
purchased to cover over-allotments, if any) (the “Units”), each comprised of one share of the Company’s
common stock, par value $0.0001 per share (the “Common Stock”), and one redeemable warrant. Each warrant (each,
a “Warrant”) entitles the holder thereof to purchase three-fourths of a share of Common Stock at a price of
$11.50 per whole share, subject to adjustment. The Units will be sold in the Public Offering pursuant to a registration statement on Form
S-1 and prospectus (the “Prospectus”) filed by the Company with the U.S. Securities and Exchange Commission
(the “Commission”) and the Company has applied to have the Units listed on The Nasdaq Global Market. Certain
capitalized terms used herein are defined in paragraph 12 hereof.

 

In order to induce the Company and the Underwriters
to enter into the Underwriting Agreement and to proceed with the Public Offering and for other good and valuable consideration, the receipt
and sufficiency of which are hereby acknowledged, each of DC Rainier SPV LLC (the “Sponsor”) and the undersigned
officers, directors and shareholders of the Company immediately prior to the Public Offering (other than the Representative) (each, an
 “Insider” and collectively, the “Insiders”), hereby agrees with the Company as follows:

 

1. The Sponsor, each Insider
and the Representative agrees that if the Company seeks stockholder approval of a proposed Business Combination, then in connection with
such proposed Business Combination, it, he or she shall (i) vote any shares of Capital Stock owned by it, him or her in favor of any proposed
Business Combination and (ii) not redeem any shares of Capital Stock owned by it, him or her in connection with such stockholder approval.
If the Company engages in a tender offer in connection with any proposed Business Combination, the Sponsor and each Insider agrees that
it, he or she will not seek to sell its, his or her shares of Capital Stock to the Company in connection with such tender offer.

 

2. The Sponsor and each
Insider hereby agrees that in the event that the Company fails to consummate a Business Combination within 15 months from the
closing of the Public Offering, or such later period approved by the Company’s stockholders in accordance with the
Company’s amended and restated certificate of incorporation (the “Charter”), the Sponsor and each
Insider shall take all reasonable steps to cause the Company to (i) cease all operations except for the purpose of winding up, (ii)
as promptly as reasonably possible but not more than 10 Business Days thereafter, subject to lawfully available funds therefor,
redeem 100% of the Common Stock sold as part of the Units in the Public Offering (the “Offering Shares”),
at a per-share price, payable in cash, equal to the aggregate amount then on deposit in the Trust Account (as defined below),
including interest earned on the funds held in the Trust Account and not previously released to the Company to pay its taxes (as
described in the Prospectus) (less up to $100,000 of interest to pay dissolution expenses), divided by the number of then
outstanding Offering Shares, which redemption will completely extinguish all Public Stockholders’ rights as stockholders
(including the right to receive further liquidation distributions, if any), subject to applicable law, and (iii) as promptly as
reasonably possible following such redemption, subject to the approval of the Company’s remaining stockholders and the
Company’s board of directors, dissolve and liquidate, subject in each case to the Company’s obligations under Delaware
law to provide for claims of creditors and other requirements of applicable law. The Sponsor and each Insider agrees not to propose
any amendment to the Charter to modify (i) the substance or timing of the ability of holders of Offering Shares to seek redemption
in connection with a Business Combination or the Company’s obligation to redeem 100% of the Offering Shares if the Company
does not complete a Business Combination by the date set forth in the Charter or (ii) the other provisions relating to
stockholders’ rights or pre-initial Business Combination activities, unless the Company provides Public Stockholders with the
opportunity to redeem their shares of Common Stock upon approval of any such amendment at a per-share price, payable in cash, equal
to the aggregate amount then on deposit in the Trust Account, including interest earned on the funds held in the Trust Account and
not previously released to the Company to pay its taxes (as described in the Prospectus), divided by the number of then outstanding
Offering Shares.

 

     

     

    

 

The Sponsor, each Insider
and the Representative acknowledges that, with respect to the Founder Shares held by it, him or her, it, he or she has no right, title,
interest or claim of any kind in or to any monies held in the Trust Account as a result of any liquidation of the Company (although the
Sponsor, the Insiders, the Representative and their respective affiliates shall be entitled to redemption and liquidation rights with
respect to any Offering Shares it or they hold if the Company fails to consummate a Business Combination within the time period set forth
in the Charter). The Sponsor, each Insider and the Representative hereby further waives, with respect to any shares of Capital Stock held
by it, him or her, if any, any redemption rights it, he or she may have in connection with the consummation of a Business Combination,
including, without limitation, any such rights available in the context of a stockholder vote to approve such Business Combination or
a stockholder vote to approve an amendment to the Charter to (i) modify the substance or timing of the Company’s obligation to redeem
100% of the Offering Shares if the Company has not consummated a Business Combination within the time period set forth in the Charter
or in the context of a tender offer made by the Company to purchase shares of Capital Stock or (ii) with respect to any other provision
relating to stockholders’ rights or pre-initial Business Combination activity.

 

3. During the period commencing
on the effective date of the Underwriting Agreement and ending 180 days after such date, the Sponsor and each Insider shall not, without
the prior written consent of the Representative, (i) sell, offer to sell, contract or agree to sell, hypothecate, pledge, grant any option,
right or warrant to purchase, lend or otherwise dispose of or agree to dispose of, directly or indirectly, any Units, shares of Common
Stock, Founder Shares, Warrants or any securities convertible into, or exercisable, or exchangeable for, shares of Common Stock owned
by it, him or her, (ii) establish or increase a put equivalent position or liquidate or decrease a call equivalent position within the
meaning of Section 16 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), and the rules
and regulations of the Commission promulgated thereunder, with respect to any Units, shares of Common Stock, Founder Shares, Warrants
or any securities convertible into, or exercisable, or exchangeable for, shares of Common Stock owned by it, him or her, (iii) enter
into any swap or other arrangement that transfers to another, in whole or in part, any of the economic consequences of ownership of any
Units, shares of Common Stock, Founder Shares, Warrants or any securities convertible into, or exercisable, or exchangeable for, shares
of Common Stock owned by it, him or her, whether any such transaction is to be settled by delivery of such securities, in cash or otherwise,
(iv) file or cause to be filed any registration statement with the Commission relating to the offering of any Units, shares of Common
Stock, Founder Shares, Warrants or any securities convertible into, or exercisable, or exchangeable for, shares of Common Stock owned
by it, him or her, (v) complete any offering of debt securities of the Company, other than entering into a line of credit with a traditional
bank, or (vi) publicly announce any intention to effect any transaction specified in clause (i), (ii), (iii), (iv) or (v). Each of the
Insiders and the Sponsor acknowledges and agrees that, prior to the effective date of any release or waiver of the restrictions set forth
in this paragraph 3 or paragraph 7 below, the Company shall announce the impending release or waiver by press release through a major
news service at least two Business Days before the effective date of the release or waiver. Any release or waiver granted shall only
be effective two Business Days after the publication date of such press release. The provisions of this paragraph will not apply if the
release or waiver is effected solely to permit a transfer not for consideration and the transferee has agreed in writing to be bound
by the same terms described in this Letter Agreement to the extent and for the duration that such terms remain in effect at the time
of the transfer.

 

    2 

     

    

 

4. In the event of the liquidation
of the Trust Account upon the failure of the Company to consummate its initial Business Combination within the time period set forth in
the Charter, the Sponsor (the “Indemnitor”) agrees to indemnify and hold harmless the Company against any and
all loss, liability, claim, damage and expense whatsoever (including, but not limited to, any and all legal or other expenses reasonably
incurred in investigating, preparing or defending against any litigation, whether pending or threatened) to which the Company may become
subject as a result of any claim by (i) any third party for services rendered or products sold to the Company or (ii) any prospective
target business with which the Company has entered into a written letter of intent, confidentiality or other similar agreement or Business
Combination agreement (a “Target”); provided, however, that such indemnification of the Company by the Indemnitor
(x) shall apply only to the extent necessary to ensure that such claims by a third party or a Target do not reduce the amount of funds
in the Trust Account to below the lesser of (i) $10.15 per Offering Share and (ii) the actual amount per Offering Share held in the Trust
Account as of the date of the liquidation of the Trust Account, if less than $10.15 per Offering Share is then held in the Trust Account
due to reductions in the value of the trust assets, less interest earned on the Trust Account which may be withdrawn to pay taxes, (y)
shall not apply to any claims by a third party or a Target which executed a waiver of any and all rights to the monies held in the Trust
Account (whether or not such waiver is enforceable) and (z) shall not apply to any claims under the Company’s indemnity of the Underwriters
against certain liabilities, including liabilities under the Securities Act of 1933, as amended. The Indemnitor shall have the right to
defend against any such claim with counsel of its choice reasonably satisfactory to the Company if, within 15 days following written receipt
of notice of the claim to the Indemnitor, the Indemnitor notifies the Company in writing that it shall undertake such defense.

 

5. To the extent that the
Underwriters do not exercise their over-allotment option to purchase up to an additional 2,250,000 Units within 45 days from the date
of the Prospectus (and as further described in the Prospectus), the Initial Stockholders agree to forfeit, at no cost, a number of Founder
Shares in the aggregate equal to 562,500 multiplied by a fraction, (i) the numerator of which is 2,250,000 minus the number of Units purchased
by the Underwriters upon the exercise of their over-allotment option, and (ii) the denominator of which is 2,250,000. The forfeiture will
be adjusted to the extent that the over-allotment option is not exercised in full by the Underwriters so that the Initial Stockholders
will own an aggregate of 20.0% of the Company’s issued and outstanding shares of Capital Stock after the Public Offering.

 

6. (a) The Sponsor and the
Insiders hereby agree not to participate in the formation of, or become an officer or director of, any special purpose acquisition company
with a class of securities registered under the Exchange Act, other than the Company, until the Company has entered into a definitive
agreement regarding an initial Business Combination or the Company has failed to complete an initial Business Combination within 15 months
after the closing of the Public Offering, as such period may be extended by Company stockholder approval.

 

    3 

     

    

 

(b) The Sponsor and the Insiders
hereby agree to offer all suitable Business Combination opportunities to the Company before any other person or company until the consummation
by the Company of an initial Business Combination, subject to any pre-existing contractual or fiduciary obligations they may have (which
pre-existing fiduciary duties and any potential conflicts of interest arising therefrom have been previously disclosed to the Representative),
on customary terms reasonably acceptable to the Representative.

 

(c) The Sponsor and each Insider
hereby agrees and acknowledges that: (i) the Underwriters and the Company would be irreparably injured in the event of a breach by the
Sponsor or an Insider of its, his or her obligations under paragraphs 1, 2, 3, 4, 5, 6(a), 6(b), 7(a), 7(b), and 9, as applicable, of
this Letter Agreement (ii) monetary damages may not be an adequate remedy for such breach and (iii) the non-breaching party shall be entitled
to injunctive relief, in addition to any other remedy that such party may have in law or in equity, in the event of such breach.

 

7. (a) The Sponsor, each Insider
and the Representative agrees that it, he or she shall not Transfer any Founder Shares (or shares of Common Stock issuable upon conversion
thereof) until the earlier of (A) one year after the completion of the Company’s initial Business Combination or (B) subsequent
to the Company’s initial Business Combination, (x) if the last reported sale price of the Common Stock equals or exceeds $12.00
per share (as adjusted for stock splits, stock dividends, reorganizations, recapitalizations and the like) for any 20 trading days within
any 30-trading day period commencing at least 150 days after the Company’s initial Business Combination or (y) the date on which
the Company completes a liquidation, merger, capital stock exchange, reorganization or other similar transaction that results in all of
the Company’s stockholders having the right to exchange their shares of Common Stock for cash, securities or other property (the
 “Founder Shares Lock-up Period”).

 

(b) The Sponsor and each Insider
agrees that it, he or she shall not Transfer any Private Placement Units (including the shares of Common Stock underlying the Private
Warrants), until 30 days after the Company’s completion of its initial Business Combination (the “Private Placement
Units Lock-up Period”, together with the Founder Shares Lock-up Period, the “Lock-up Periods”).

 

(c) Notwithstanding the provisions
set forth in paragraphs 7(a) and (b), Transfers of the Founder Shares, the Private Placement Units and the shares of Common Stock issued
or issuable upon the exercise or conversion of the Private Warrants or the Founder Shares and that are held by the Sponsor, any Insider,
the Representative or any of their permitted transferees (that have complied with this paragraph 7(c)), are permitted (a) to the Company’s
officers or directors, any affiliate or family member of any of the Company’s officers or directors, any affiliate of the Sponsor
or any member of the Sponsor; (b) in the case of an individual, by gift to a member of such individual’s immediate family or to
a trust, the beneficiary of which is a member of such individual’s immediate family, an affiliate of such individual or to a charitable
organization; (c) in the case of an individual, by virtue of laws of descent and distribution upon death of such individual; (d) in the
case of an individual, pursuant to a qualified domestic relations order; (e) by private sales or transfers made in connection with the
consummation of the Company’s initial Business Combination at prices no greater than the price at which the Founder Shares, shares
of Common Stock or Private Units were originally purchased; (f) in the event of the Company’s liquidation prior to the completion
of an initial Business Combination; or (g) by virtue of the laws of the State of Delaware or the Sponsor’s limited liability company
agreement upon dissolution of the Sponsor; provided, however, that in the case of clauses (a) through (e) or (g), any such permitted transferees
must enter into a written agreement with the Company agreeing to be bound by the transfer restrictions in this paragraph 7(c) and the
other restrictions contained in this Letter Agreement.

 

8. The Sponsor and each Insider
represents and warrants that it, he or she has never been suspended or expelled from membership in any securities or commodities exchange
or association or had a securities or commodities license or registration denied, suspended or revoked. Each Insider’s biographical
information furnished to the Company (including any such information included in the Prospectus) is true and accurate in all respects
and does not omit any material information with respect to the Insider’s background. Each Insider’s questionnaire furnished
to the Company is true and accurate in all respects. Each Insider represents and warrants that: it, he or she is not subject to or a
respondent in any legal action for, any injunction, cease-and-desist order or order or stipulation to desist or refrain from any act
or practice relating to the offering of securities in any jurisdiction; it, he or she has never been convicted of, or pleaded guilty
to, any crime (i) involving fraud, (ii) relating to any financial transaction or handling of funds of another person, or (iii) pertaining
to any dealings in any securities and it, he or she is not currently a defendant in any such criminal proceeding.

 

    4 

     

    

 

9. Except as disclosed
in the Prospectus, neither the Sponsor nor any officer, nor any affiliate of the Sponsor or any officer, nor any director of the
Company, shall receive from the Company any finder’s fee, reimbursement, consulting fee, monies in respect of any repayment of
a loan or other compensation prior to, or in connection with any services rendered in order to effectuate, the consummation of the
Company’s initial Business Combination (regardless of the type of transaction that it is), other than the following, none of
which will be made from the proceeds held in the Trust Account prior to the completion of the initial Business Combination:
repayment of a loan and advances up to an aggregate of $50,000 made to the Company by the Sponsor; payment to an affiliate of the
Sponsor for certain office space, utilities and secretarial and administrative support as may be reasonably required by the Company
for a total of $10,000 per month; reimbursement for any reasonable out-of-pocket expenses related to identifying, investigating and
consummating an initial Business Combination; and repayment of loans, if any, and on such terms as to be determined by the Company
from time to time, made by the Sponsor or an affiliate of the Sponsor or any of the Company’s officers or directors to finance
transaction costs in connection with an intended initial Business Combination, provided, that, if the Company does not consummate an
initial Business Combination, a portion of the working capital held outside the Trust Account may be used by the Company to repay
such loaned amounts so long as no proceeds from the Trust Account are used for such repayment.

 

11. The Sponsor and each Insider
has full right and power, without violating any agreement to which it is bound (including, without limitation, any non-competition or
non-solicitation agreement with any employer or former employer), to enter into this Letter Agreement and, as applicable, to serve as
an officer or director of the Company and hereby consents to being named in the Prospectus as an officer or director of the Company.

 

12. (i) “Business
Combination” shall mean a merger, capital stock exchange, asset acquisition, stock purchase, reorganization or similar business
combination, involving the Company and one or more businesses; (ii) “Business Day” means each day that is not
a Saturday, Sunday or other day on which banking institutions in The City of New York, New York, are authorized or required by law to
close; (iii) “Capital Stock” shall mean, collectively, the Common Stock and the Founder Shares; (iv) “Founder
Shares” shall mean the 4,312,500 shares of Common Stock, par value $0.0001 per share, (up to 562,500 Shares of which are
subject to complete or partial forfeiture by the Initial Stockholders, if the over-allotment option is not exercised by the Underwriters)
outstanding immediately prior to the consummation of the Public Offering; (v) “Initial Stockholders” shall mean
the Sponsor, the Representative and any Insider that holds Founder Shares prior to the consummation of the Public Offering; (vi) “Private
Placement Units” shall refer to the aggregate of 476,200 units (or 509,950 units if the over-allotment option is exercised
in full) that the Sponsor, Matthew Kearney and Young Cho have collectively agreed to purchase for an aggregate purchase price of $4,762,000,
or $5,099,500 if the over-allotment option is exercised in full or $10.00 per Unit, in a private placement that shall occur simultaneously
with the consummation of the Public Offering; (vii) “Private Warrants” shall mean the Warrants underlying the
Private Placement Units; (viii) “Public Stockholders” shall mean the holders of the Offering Shares; (ix) “Trust
Account” shall mean the trust fund into which a portion of the net proceeds of the Public Offering and the sale of Private
Placement Units shall be deposited; and (x) “Transfer” shall mean the (a) sale of, offer to sell, contract or
agreement to sell, hypothecate, pledge, grant of any option to purchase or otherwise dispose of or agreement to dispose of, directly or
indirectly, or establishment or increase of a put equivalent position or liquidation with respect to or decrease of a call equivalent
position within the meaning of Section 16 of the Exchange Act, and the rules and regulations of the Commission promulgated thereunder
with respect to, any security, (b) entry into any swap or other arrangement that transfers to another, in whole or in part, any of the
economic consequences of ownership of any security, whether any such transaction is to be settled by delivery of such securities, in cash
or otherwise, or (c) public announcement of any intention to effect any transaction specified in clause (a) or (b).

 

    5 

     

    

 

13. The Company will maintain
an insurance policy or policies providing directors’ and officers’ liability insurance, and each Director shall be covered
by such policy or policies, in accordance with its or their terms, to the maximum extent of the coverage available for any of the Company’s
directors or officers.

 

14. This Letter Agreement
constitutes the entire agreement and understanding of the parties hereto in respect of the subject matter hereof and supersedes all prior
understandings, agreements, or representations by or among the parties hereto, written or oral, to the extent they relate in any way to
the subject matter hereof or the transactions contemplated hereby. This Letter Agreement may not be changed, amended, modified or waived
(other than to correct a typographical error) as to any particular provision, except by a written instrument executed by all parties hereto.

 

15. No party hereto may assign
either this Letter Agreement or any of its rights, interests, or obligations hereunder without the prior written consent of the other
parties. Any purported assignment in violation of this paragraph shall be void and ineffectual and shall not operate to transfer or assign
any interest or title to the purported assignee. This Letter Agreement shall be binding on the Sponsor and each Insider and their respective
successors, heirs and assigns and permitted transferees.

 

16. Nothing in this Letter
Agreement shall be construed to confer upon, or give to, any person or corporation other than the parties hereto any right, remedy or
claim under or by reason of this Letter Agreement or of any covenant, condition, stipulation, promise or agreement hereof. All covenants,
conditions, stipulations, promises and agreements contained in this Letter Agreement shall be for the sole and exclusive benefit of the
parties hereto and their successors, heirs, personal representatives and assigns and permitted transferees.

 

17. This Letter Agreement
may be executed in any number of original or facsimile counterparts and each of such counterparts shall for all purposes be deemed to
be an original, and all such counterparts shall together constitute but one and the same instrument.

 

18. This Letter Agreement
shall be deemed severable, and the invalidity or unenforceability of any term or provision hereof shall not affect the validity or enforceability
of this Letter Agreement or of any other term or provision hereof. Furthermore, in lieu of any such invalid or unenforceable term or provision,
the parties hereto intend that there shall be added as a part of this Letter Agreement a provision as similar in terms to such invalid
or unenforceable provision as may be possible and be valid and enforceable.

 

19. This Letter Agreement
shall be governed by and construed and enforced in accordance with the laws of the State of New York, without giving effect to conflicts
of law principles that would result in the application of the substantive laws of another jurisdiction. The parties hereto (i) all agree
that any action, proceeding, claim or dispute arising out of, or relating in any way to, this Letter Agreement shall be brought and enforced
in the courts of New York City, in the State of New York, and irrevocably submit to such jurisdiction and venue, which jurisdiction and
venue shall be exclusive and (ii) waive any objection to such exclusive jurisdiction and venue or that such courts represent an inconvenient
forum.

 

    6 

     

    

 

20. Any notice, consent or
request to be given in connection with any of the terms or provisions of this Letter Agreement shall be in writing and shall be sent by
express mail or similar private courier service, by certified mail (return receipt requested), by hand delivery or facsimile transmission.

 

21. This Letter Agreement
shall terminate on the earlier of (i) the expiration of the Lock-up Periods or (ii) the liquidation of the Company; provided, however,
that this Letter Agreement shall earlier terminate in the event that the Public Offering is not consummated by [ ], 2023; provided further
that paragraph 4 of this Letter Agreement shall survive such liquidation.

 

22. The Company, the Sponsor
and each Insider hereby acknowledges and agrees that the the Underwriters are third party beneficiaries of this Letter Agreement.

 

[Signature Page Follows]

 

    7 

     

    

 

	 	Sincerely,

 

	 	DC Rainier SPV LLC

 

	 	By: Dominion Capital LLC, its Manager
	 	By: Dominion Capital Holdings LLC, its Manager

 

		By:	

		Name:	

		Title:	

 

	 	 
	 	Matthew Kearney 

 

	 	 
	 	Young Cho

 

	 	 
	 	Christina Favilla

 

	 	 
	 	Otto Risbakk

 

	 	 
	 	Jeffery Bistrong 

 

	 	A.G.P./ALLIANCE GLOBAL PARTNERS, as Representative
of the several Underwriters

 

		By:	

		Name:	

		Title:	

 

[Signature Page to Letter Agreement]

 

     

     

    

 

	 	Acknowledged and Agreed:
	 	 	 
	 	MOUNT RAINIER ACQUISITION CORP.
	 	 
	 	By:	 
	 	 	Name: 
	 	 	Title:

 

[Signature Page to Letter Agreement]Exhibit 10.2

 

INVESTMENT MANAGEMENT TRUST AGREEMENT

 

This Investment Management
Trust Agreement (this “Agreement”) is made effective as of [●], 2021, by and between Mount Rainier Acquisition
Corp., a Delaware corporation (the “Company”), and American Stock Transfer & Trust Company, LLC , a New
York limited liability trust company (the “Trustee”).

 

WHEREAS, the Company’s
registration statement on Form S-1, File No. 333-256816 (the “Registration Statement”) and prospectus
(the “Prospectus”) for the initial public offering of the Company’s units (the “Units”),
each of which consists of one share of the Company’s common stock, par value $0.0001 per share (the “Common Stock”),
and one redeemable warrant to purchase three-fourths (3/4) of a share of Common Stock at a price of $11.50 per whole share, , subject
to adjustment (such initial public offering hereinafter referred to as the “Offering”), has been declared effective
as of the date hereof by the U.S. Securities and Exchange Commission;

 

WHEREAS, the Company has entered
into an Underwriting Agreement, dated [●], 2021 (the “Underwriting Agreement”), with A.G.P./Alliance Global
Partners, as representative (the “Representative”) of the several underwriters named therein (the “Underwriters”);

 

WHEREAS, as described in the
Prospectus, $150,000,000 of the gross proceeds of the Offering and sale of the Private Units (as defined in the Underwriting
Agreement) (or $172,500,000, if the Underwriters’ over-allotment option is exercised in full) will be delivered to the Trustee to
be deposited and held in a segregated trust account located at all times in the United States (the “Trust Account”)
for the benefit of the Company, the holders of the Common Stock included in the Units issued in the Offering and the Underwriters as hereinafter
provided (the amount to be delivered to the Trustee (and any interest subsequently earned thereon) is referred to herein as the “Property,”
the stockholders for whose benefit the Trustee shall hold the Property will be referred to as the “Public Stockholders,”
and the Public Stockholders, the Company and the Underwriters will be referred to together as the “Beneficiaries”);

 

WHEREAS, pursuant to the Underwriting
Agreement, a portion of the Property equal to $6,000,000, or $6,900,000 if the Underwriters’ over-allotment option is exercised
in full, is attributable to a business combination fee that will be payable by the Company to the Representative upon and concurrently
with the consummation of the Business Combination (as defined below) (the “Business Combination Fee”); and

 

WHEREAS, the Company and the
Trustee desire to enter into this Agreement to set forth the terms and conditions pursuant to which the Trustee shall hold the Property.

 

NOW THEREFORE, IT IS AGREED:

 

1.             
Agreements and Covenants of Trustee. The Trustee hereby agrees and covenants to:

 

     

     

    

 

(a)          Hold
the Property in trust for the Beneficiaries in accordance with the terms of this Agreement in the Trust Account, which Trust Account
shall be established by the Trustee in the United States at [●] and at a brokerage institution selected by the Trustee that is
reasonably satisfactory to the Company;

 

(b)         
Manage, supervise and administer the Trust Account subject to the terms and conditions set forth herein;

 

(c)         
In a timely manner, upon the written instruction of the Company, invest and reinvest the Property solely in United States
government securities within the meaning of Section 2(a)(16) of the Investment Company Act of 1940, as amended (the “Investment
Company Act”), having a maturity of 180 days or less, or in money market funds meeting the conditions of paragraphs (d)(1),
(d)(2), (d)(3) and (d)(4) of Rule 2a-7 promulgated under the Investment Company Act (or any successor rule), which invest only in direct
U.S. government treasury obligations, as determined by the Company, it being understood that the Trustee has no obligation to monitor
or question the Company’s determination that an investment is in compliance with the foregoing clause; Company shall not instruct
the Trustee to invest in any other securities or assets; it being understood that the Trust Account will earn no interest while account
funds are uninvested awaiting the Company’s instructions hereunder and the Trustee may earn bank credits or other consideration
during such periods;

 

(d)        
Collect and receive, when due, all interest or other income arising from the Property, which shall become part of the “Property,”
as such term is used herein;

 

(e)         
Promptly notify the Company and the Representative of all communications received by the Trustee with respect to any Property
requiring action by the Company;

 

(f)          
Supply any necessary information or documents as may be requested by the Company (or its authorized agents) in connection
with the Company’s preparation of the tax returns relating to assets held in the Trust Account;

 

(g)        
Participate in any plan or proceeding for protecting or enforcing any right or interest arising from the Property if, as
and when instructed by the Company to do so;

 

(h)         
Render to the Company, and to such other person as the Company may instruct, monthly written statements of the activities
of, and amounts in, the Trust Account reflecting all receipts and disbursements of the Trust Account;

 

    2

     

    

 

(i)           Commence
liquidation of the Trust Account only after and promptly after (x) receipt of, and only in accordance with, the terms of a
letter from the Company (“Termination Letter”) in a form substantially similar to that attached hereto as
either Exhibit A or Exhibit B, as applicable, signed on behalf of the Company by its Chief Executive
Officer, Chief Financial Officer, President, Vice President, Secretary or Chairman of the board of directors of the Company (the
 “Board”) or other authorized officer of the Company, and complete the liquidation of the Trust Account and
distribute the Property in the Trust Account, including interest not previously released to the Company to pay its taxes (less up to
$100,000 of interest that may be released to the Company to pay dissolution expenses in the case of a Termination Letter in the form
of Exhibit B hereto), only as directed in the Termination Letter and the other documents referred to therein, or (y) upon the date
which is, the later of (1) 15 months after the closing of the Offering and (2) such later date as may be approved by the
Company’s stockholders in accordance with the Company’s amended and restated certificate of incorporation (the
 “Amended and Restated Certificate of Incorporation”) if a Termination Letter has not been received by the
Trustee prior to such date, in which case the Trust Account shall be liquidated in accordance with the procedures set forth in the
form of letter attached hereto as Exhibit B and the Property in the Trust Account, including interest not previously
released to the Company to pay its taxes (less up to $100,000 of interest that may be released to the Company to pay dissolution
expenses) shall be distributed to the Public Stockholders of record as of such date; provided, however, that in the
event the Trustee receives a Termination Letter in a form substantially similar to Exhibit B hereto, or if the Trustee
begins to liquidate the Property because it has received no such Termination Letter by the date specified in clause (y) of this
Section 1(i), the Trustee shall keep the Trust Account open until twelve (12) months following the date the Property has been
distributed to the Public Stockholders;

 

(j)          
Upon written request from the Company, which may be given from time to time in a form substantially similar to that attached
hereto as Exhibit C, withdraw from the Trust Account and distribute to the Company the amount of interest earned on the Property
requested by the Company to cover any tax obligation owed by the Company as a result of assets of the Company or interest or other income
earned on the Property, which amount shall be delivered directly to the Company by electronic funds transfer or other method of prompt
payment, and the Company shall forward such payment to the relevant taxing authority; provided, however, that to the extent
there is not sufficient cash in the Trust Account to pay such tax obligation, the Trustee shall liquidate such assets held in the Trust
Account as shall be designated by the Company in writing to make such distribution, so long as such distribution shall not result in a
reduction in the principal amount initially deposited in the Trust Account; provided, further, that if the tax to be paid
is a franchise tax, the written request by the Company to make such distribution shall be accompanied by a copy of the franchise tax bill
from the State of Delaware for the Company (it being acknowledged and agreed that any such amount in excess of interest income earned
on the Property shall not be payable from the Trust Account). The written request of the Company referenced above shall constitute presumptive
evidence that the Company is entitled to said funds, and the Trustee shall have no responsibility to look beyond said request;

 

(k)         
Upon written request from the Company, which may be given from time to time in a form substantially similar to that attached
hereto as Exhibit D, distribute on behalf of the Company the amount requested by the Company to be used to redeem shares of Common
Stock from Public Stockholders properly submitted for redemption in connection with a stockholder vote to approve (i) an amendment to
the Amended and Restated Certificate of Incorporation to modify the substance or timing of the ability of Public Stockholders to seek
redemption in connection with an initial Business Combination or the Company’s obligation to redeem 100% of its public shares of
Common Stock if the Company has not consummated an initial Business Combination within such time as is described in the Amended and Restated
Certificate of Incorporation or (ii) an amendment with respect to any other provision of the Amended and Restated Certificate of Incorporation
relating to stockholders’ rights or pre-initial Business Combination activity. The written request of the Company referenced above
shall constitute presumptive evidence that the Company is entitled to distribute said funds, and the Trustee shall have no responsibility
to look beyond said request; and

 

(l)          
Not make any withdrawals or distributions from the Trust Account other than pursuant to Section 1(i), (j),
(k) or (l) above.

 

    3

     

    

 

2.             
Agreements and Covenants of the Company. The Company hereby agrees and covenants to:

 

(a)         
Give all instructions to the Trustee hereunder in writing, signed by the Company’s Chairman of the Board, Chief Executive
Officer, Chief Financial Officer, President, Executive Vice President, Vice President or Secretary. In addition, except with respect to
its duties under Sections 1(i), 1(j), 1(k) and 1(l) hereof, the Trustee shall be entitled to rely on, and shall be
protected in relying on, any verbal or telephonic advice or instruction which it, in good faith and with reasonable care, believes to
be given by any one of the persons authorized above to give written instructions, provided that the Company shall promptly confirm such
instructions in writing;

 

(b)         Subject
to Section 4 hereof, hold the Trustee harmless and indemnify the Trustee from and against any and all expenses,
including reasonable counsel fees and disbursements, or losses suffered by the Trustee in connection with any action taken by it
hereunder and in connection with any action, suit or other proceeding brought against the Trustee involving any claim, or in
connection with any claim or demand, which in any way arises out of or relates to this Agreement, the services of the Trustee
hereunder, or the Property or any interest earned on the Property, except for expenses and losses resulting from the Trustee’s
gross negligence, fraud or willful misconduct (as determined by a court of competent jurisdiction in a final and non-appealable decision). Promptly after the receipt by the Trustee of notice of demand or claim or the
commencement of any action, suit or proceeding, pursuant to which the Trustee intends to seek indemnification under this Section 2(b),
it shall notify the Company in writing of such claim (hereinafter referred to as the “Indemnified Claim”).
The Trustee shall have the right to conduct and manage the defense against such Indemnified Claim; provided that the Trustee
shall obtain the consent of the Company with respect to the selection of counsel, which consent shall not be unreasonably withheld.
The Trustee may not agree to settle any Indemnified Claim without the prior written consent of the Company, which such consent shall
not be unreasonably withheld. The Company may participate in such action with its own counsel;

 

(c)          Pay
the Trustee the fees set forth on Schedule A hereto, including an initial acceptance fee, annual administration fee, and
transaction processing fee which fees shall be subject to modification by the parties from time to time. It is expressly understood that
the Property shall not be used to pay such fees unless and until the closing of the Business Combination. The Company shall pay the Trustee
the initial acceptance fee and the first annual administration fee at the consummation of the Offering. The Trustee shall refund to the
Company the annual administration fee (on a pro rata basis) with respect to any period after the liquidation of the Trust Account. The
Company shall not be responsible for any other fees or charges of the Trustee except as set forth in this Section 2(c), Schedule
A and as may be provided in Section 2(b) hereof;

 

(d)        
In connection with any vote of the Company’s stockholders regarding a merger, capital stock exchange, asset acquisition,
stock purchase, reorganization or similar business combination involving the Company and one or more businesses (a “Business
Combination”), provide to the Trustee an affidavit or certificate of the inspector of elections for the stockholder meeting
verifying the vote of such stockholders regarding such Business Combination;

 

    4

     

    

 

(e)         
Provide the Representative with a copy of any Termination Letter(s) and/or any other correspondence that is sent to the
Trustee with respect to any proposed withdrawal from the Trust Account promptly after it issues the same;

 

(f)         
Unless otherwise agreed between the Company and the Representative, ensure that any Instruction Letter (as defined in Exhibit
A) delivered in connection with a Termination Letter in the form of Exhibit A expressly provides that the Business Combination Fee is
paid directly to the account or accounts directed by the Representative prior to any transfer of the funds held in the Trust Account to
the Company or any other person;

 

(g)          Instruct
the Trustee to make only those distributions that are permitted under this Agreement, and refrain from instructing the Trustee to make
any distributions that are not permitted under this Agreement; and

 

(h)          Within
four (4) business days after the Underwriters exercise their over-allotment option in connection with the Offering (or any unexercised
portion thereof) or such over-allotment expires, provide the Trustee with a notice in writing of the total amount of the Business Combination
Fee, which shall in no event be less than $6,000,000.

 

3.             
Limitations of Liability. The Trustee shall have no responsibility or liability to:

 

(a)         
Imply obligations, perform duties, inquire or otherwise be subject to the provisions of any agreement or document other
than this Agreement and that which is expressly set forth herein;

 

(b)         
Take any action with respect to the Property, other than as directed in Section 1 hereof, and the Trustee shall
have no liability to any third party except for liability arising out of the Trustee’s gross negligence, fraud or willful misconduct,
and in no event shall the Trustee be liable for the selection of investments or for investment losses incurred thereon or for losses incurred
as a result of the liquidation of any such investment prior to its maturity date or the failure of the Company to provide timely written
investment instruction;

 

(c)         
Institute any proceeding for the collection of any principal and income arising from, or institute, appear in or defend
any proceeding of any kind with respect to, any of the Property unless and until it shall have received instructions from the Company
given as provided herein to do so and the Company shall have advanced or guaranteed to it funds sufficient to pay any expenses incident
thereto;

 

(d)         
Refund any depreciation in principal of any Property;

 

(e)        
Assume that the authority of any person designated by the Company to give instructions hereunder shall not be continuing
unless provided otherwise in such designation, or unless the Company shall have delivered a written revocation of such authority to the
Trustee;

 

    5

     

    

 

(f)          The
other parties hereto or to anyone else for any action taken or omitted by it, or any action suffered by it to be taken or omitted,
in good faith and in the Trustee’s best judgment, except for the Trustee’s gross negligence, fraud or willful
misconduct. The Trustee may rely conclusively and shall be protected in acting upon any order, notice, demand, certificate, opinion
or advice of counsel (including counsel chosen by the Trustee, which counsel may be the Company’s counsel), statement,
instrument, report or other paper or document (not only as to its due execution and the validity and effectiveness of its
provisions, but also as to the truth and acceptability of any information therein contained) which the Trustee believes, in good
faith and with reasonable care, to be genuine and to be signed or presented by the proper person or persons. The Trustee shall not
be bound by any notice or demand, or any waiver, modification, termination or rescission of this Agreement or any of the terms
hereof, unless evidenced by a written instrument delivered to the Trustee, signed by the proper party or parties and, if the duties
or rights of the Trustee are affected, unless it shall give its prior written consent thereto;

 

(g)        
Verify the accuracy of the information contained in the Registration Statement;

 

(h)         
Provide any assurance that any Business Combination entered into by the Company or any other action taken by the Company
is as contemplated by the Registration Statement;

 

(i)          
File information returns with respect to the Trust Account with any local, state or federal taxing authority or provide
periodic written statements to the Company documenting the taxes payable by the Company, if any, relating to any interest income earned
on the Property;

 

(j)          
Prepare, execute and file tax reports, income or other tax returns and pay any taxes with respect to any income generated
by, and activities relating to, the Trust Account, regardless of whether such tax is payable by the Trust Account or the Company, including,
but not limited to, franchise and income tax obligations, except pursuant to Section 1(j) hereof; or

 

(k)         
Verify calculations, qualify or otherwise approve the Company’s written requests for distributions pursuant to Sections 1(i),
1(j), 1(k) or 1(l) hereof.

 

4.             
Trust Account Waiver. The Trustee has no right of set-off or any right, title, interest or claim of any kind (“Claim”)
to, or to any monies in, the Trust Account, and hereby irrevocably waives any Claim to, or to any monies in, the Trust Account that it
may have now or in the future. In the event the Trustee has any Claim against the Company under this Agreement, including, without limitation,
under Section 2(b) or Section 2(c) hereof, the Trustee shall pursue such Claim solely against the Company and
its assets outside the Trust Account and not against the Property or any monies in the Trust Account.

 

5.             
Termination. This Agreement shall terminate as follows:

 

(a)          If
the Trustee gives written notice to the Company that it desires to resign under this Agreement, the Company shall use its reasonable
efforts to locate a successor trustee, pending which the Trustee shall continue to act in accordance with this Agreement. At such
time that the Company notifies the Trustee that a successor trustee has been appointed and has agreed to become subject to the terms
of this Agreement, the Trustee shall transfer the management of the Trust Account to the successor trustee, including but not
limited to the transfer of copies of the reports and statements relating to the Trust Account, whereupon this Agreement shall
terminate; provided, however, that in the event that the Company does not locate a successor trustee within ninety
(90) days of receipt of the resignation notice from the Trustee, the Trustee may submit an application to have the Property
deposited with any court in the State of New York or with the United States District Court for the Southern District of New York and
upon such deposit, the Trustee shall be immune from any liability whatsoever; or

 

    6

     

    

 

(b)        
At such time that the Trustee has completed the liquidation of the Trust Account and its obligations in accordance with
the provisions of Section 1(i) hereof and distributed the Property in accordance with the provisions of the Termination Letter,
this Agreement shall terminate except with respect to Section 2(b).

 

6.             
Miscellaneous.

 

(a)         
The Company and the Trustee each acknowledge that the Trustee will follow the security procedures set forth below with respect
to funds transferred from the Trust Account. The Company and the Trustee will each restrict access to confidential information relating
to such security procedures to authorized persons. Each party must notify the other party immediately if it has reason to believe unauthorized
persons may have obtained access to such confidential information, or of any change in its authorized personnel. In executing funds transfers,
the Trustee shall rely upon all information supplied to it by the Company, including, account names, account numbers, and all other identifying
information relating to a Beneficiary, Beneficiary’s bank or intermediary bank. Except for any liability arising out of the Trustee’s
gross negligence, fraud or willful misconduct, the Trustee shall not be liable for any loss, liability or expense resulting from any error
in the information or transmission of the funds.

 

(b)        
This Agreement shall be governed by and construed and enforced in accordance with the laws of the State of New York, without
giving effect to conflicts of law principles that would result in the application of the substantive laws of another jurisdiction. This
Agreement may be executed in several original or facsimile counterparts, each one of which shall constitute an original, and together
shall constitute but one instrument.

 

(c)        
This Agreement contains the entire agreement and understanding of the parties hereto with respect to the subject matter
hereof. Subject to section 6(d), this Agreement or any provision hereof may only be changed, amended or modified (other than to correct
a typographical error) by a writing signed by each of the parties hereto.

 

(d)         This
Agreement or any provision hereof may only be changed, amended or modified pursuant to Section 6(c) hereof with the
Consent of the Stockholders. For purposes of this Section 6(d), the “Consent of the
Stockholders” means receipt by the Trustee of a certificate from the inspector of elections of the stockholder meeting
certifying that the Company’s stockholders of record as of a record date established in accordance with Section 213(a) of
the Delaware General Corporation Law, as amended (“DGCL”) (or any successor rule), who hold sixty-five
percent (65%) or more of all then outstanding shares of the Common Stock, of the Company voting together as a single class, have
voted in favor of such change, amendment or modification. No such amendment will affect any Public Stockholder who has otherwise
properly indicated his election to redeem his shares of Common Stock in connection with such stockholder vote. Except for any
liability arising out of the Trustee’s gross negligence, fraud or willful misconduct, the Trustee may rely conclusively on the
certification from the inspector or elections referenced above and shall be relieved of all liability to any party for executing the
proposed amendment in reliance thereon.

 

    7

     

    

 

(e)         
The parties hereto consent to the jurisdiction and venue of any state or federal court located in the City of New York,
State of New York, for purposes of resolving any disputes hereunder. AS TO ANY CLAIM, CROSS-CLAIM OR COUNTERCLAIM IN ANY WAY RELATING
TO THIS AGREEMENT, EACH PARTY WAIVES THE RIGHT TO TRIAL BY JURY.

 

(f)         
Any notice, consent or request to be given in connection with any of the terms or provisions of this Agreement shall be
in writing and shall be sent by express mail or similar private courier service, by certified mail (return receipt requested), by hand
delivery or by electronic mail:

 

if to the Trustee, to:

 

American Stock Transfer & Trust Company, LLC

6201 15th Avenue |

Brooklyn, NY 11219

Attn: Relationship Management

Email: 

 

if to the Company, to:

 

Mount Rainier Acquisition Corp.

256 W. 38th Street, 15th Floor

New York, NY 10018

Attn: Matthew Kearney, Chief Executive Officer

 

in each case, with copies to:

 

Loeb & Loeb LLP

345 Park Avenue

New York, New York 10154

Attn: Mitchell Nussbaum, Esq.

Email: 

and

A.G.P./Alliance Global Partners

590 Madison Avenue,
28th Floor 

New York, NY 10022 

Email: 

and

Manatt, Phelps & Phillips LLP

695 Town Center Drive, 14th Floor

Costa Mesa, California 92626

Attn: Thomas J. Poletti , Esq.

Email: 

 

    8

     

    

 

(g)         
Each of the Company and the Trustee hereby represents that it has the full right and power and has been duly authorized
to enter into this Agreement and to perform its respective obligations as contemplated hereunder. The Trustee acknowledges and agrees
that it shall not make any claims or proceed against the Trust Account, including by way of set-off, and shall not be entitled to any
funds in the Trust Account under any circumstance.

 

(h)        
This Agreement is the joint product of the Trustee and the Company and each provision hereof has been subject to the mutual
consultation, negotiation and agreement of such parties and shall not be construed for or against any party hereto.

 

(i)         
This Agreement may be executed in any number of counterparts, each of which shall be deemed to be an original, but all such
counterparts shall together constitute one and the same instrument. Delivery of a signed counterpart of this Agreement by facsimile or
electronic transmission shall constitute valid and sufficient delivery thereof.

 

(j)          
Each of the Company and the Trustee hereby acknowledges and agrees that the Underwriters are a third party beneficiaries
of this Agreement.

 

(k)         
Except as specified herein, no party to this Agreement may assign its rights or delegate its obligations hereunder to any
other person or entity.

[Signature Page Follows]

 

    9

     

    

 

IN WITNESS WHEREOF,
the parties have duly executed this Investment Management Trust Agreement as of the date first written above.

 

	 	AMERICAN STOCK TRANSFER & TRUST COMPANY, LLC , as Trustee
	 	 
	 	By  	 
	 	 	Name:
	 	 	Title:
	 	 
	 	MOUNT RAINIER ACQUISITION CORP.
	 	 
	 	By  	 
	 	 	Name: Matthew Kearney
	 	 	Title: Chief Executive Officer

 

[Signature Page to Investment Management Trust
Agreement]

 

     
 

     

    

 

SCHEDULE A

 

 

	Fee Item	Time and method of payment	Amount
	Initial set-up fee.	Initial closing of Offering by wire transfer.	$	$
	Trustee administration fee	Payable annually. First year fee payable, at initial closing of Offering by wire transfer, thereafter by wire transfer or check.	$	$
	Transaction processing fee for disbursements to Company under Sections 1(i), (j), (k) and (l)	Deduction by Trustee from accumulated income following disbursement made to Company under Section 1	$	$
	Paying Agent services as required pursuant to Section 1(i), (j), (k) and (l)	Billed to Company upon delivery of service pursuant to Section 1(i), (j), (k) and (l)	 	Prevailing rates

 

     
 

     

    

 

EXHIBIT A

 

[Letterhead of Company]

 

[Insert date]

 

American Stock Transfer & Trust Company, LLC

6201 15th Avenue |

Brooklyn, NY 11219

Attn: Relationship Management

 

Re:        Trust Account No.               
Termination Letter

 

Ladies and Gentlemen:

 

Pursuant to Section 1(i) of
the Investment Management Trust Agreement between Mount Rainier Acquisition Corp. (the “Company”) and American
Stock Transfer & Trust Company, LLC (the “Trustee”), dated as of [●], 2021 (the “Trust
Agreement”), this is to advise you that the Company has entered into an agreement with ___________________ (the “Target
Business”) to consummate a business combination with Target Business (the “Business Combination”)
on or about [insert date]. The Company shall notify you at least forty-eight (48) hours (or such shorter time as you may agree) in advance
of the actual date fixed for the consummation of the Business Combination (the “Consummation Date”). Capitalized
terms used but not defined herein shall have the meanings set forth in the Trust Agreement.

 

In accordance with the terms
of the Trust Agreement, we hereby authorize you to commence to liquidate all of the assets of the Trust Account on [insert date], such
that, on the Consummation Date, all of the funds held in the Trust Account will be immediately available for transfer to the account or
accounts that the Company shall direct on the Consummation Date (including as directed to it by the Representative (with respect to the
Business Combination Fee)). It is acknowledged and agreed that while the funds are on deposit in the Trust Account awaiting distribution,
the Company will not earn any interest or dividends.

 

On the Consummation Date
(i) counsel for the Company shall deliver to you written notification that the Business Combination has been consummated, or will be
consummated substantially concurrently with your transfer of funds to the accounts as directed by the Company (the
 “Notification”) and (ii) the Company shall deliver to you (a) a certificate of its Chief Executive Officer
(the “Vote Verification Certificate”), which verifies either that (i) the Business Combination has been
approved by a vote of the Company’s stockholders, if a vote is held or (ii) no vote of the Company’s stockholders for
the approval of the Business Combination is required and none has been held, and (b) a joint written instruction signed by the
Company and the Representative with respect to the transfer of the funds held in the Trust Account, including payment of amounts
owed to Public Stockholders who have properly exercised their redemption rights and payment of the Business Combination Fee to the
Representative from the Trust Account (the “Instruction Letter”). You are hereby directed and authorized
to transfer the funds held in the Trust Account immediately upon your receipt of the Notification, the Vote Verification Certificate
and the Instruction Letter, in accordance with the terms of the Instruction Letter. In the event that certain deposits held in the
Trust Account may not be liquidated by the Consummation Date without penalty, you will notify the Company in writing of the same and
the Company shall direct you as to whether such funds should remain in the Trust Account and be distributed after the Consummation
Date to the Company. Upon the distribution of all the funds, net of any payments necessary for reasonable unreimbursed expenses
related to liquidating the Trust Account, your obligations under the Trust Agreement shall be terminated.

 

     
 

     

    

 

In the event that the Business
Combination is not consummated on the Consummation Date described in the notice thereof and we have not notified you on or before the
original Consummation Date of a new Consummation Date, then upon receipt by you of written instructions from the Company, the funds held
in the Trust Account shall be reinvested as provided in Section 1(c) of the Trust Agreement on the business day immediately following
such original Consummation Date as set forth in such notice or as soon thereafter as possible.

 

	 	Very truly yours,
	 	 
	 	Mount Rainier Acquisition Corp.
	 	 
	 	By  	 
	 	 	Name:
	 	 	Title:

 

cc:        A.G.P./Alliance Global Partners

 

     
 

     

    

 

EXHIBIT B

 

[Letterhead of Company]

 

[Insert date]

 

American Stock Transfer & Trust Company, LLC

6201 15th Avenue |

Brooklyn, NY 11219

Attn: Relationship Management

 

Re:      Trust Account No.                   
Termination Letter

 

Ladies and Gentlemen:

 

Pursuant to Section 1(i)
of the Investment Management Trust Agreement between Mount Rainier Acquisition Corp. (the “Company”) and American
Stock Transfer & Trust Company, LLC (the “Trustee”), dated as of [●], 2021 (the “Trust
Agreement”), this is to advise you that the Company has been unable to effect a Business Combination within the time frame
specified in the Company’s Amended and Restated Certificate of Incorporation, as described in the Company’s Prospectus relating
to the Offering. Capitalized terms used but not defined herein shall have the meanings set forth in the Trust Agreement.

 

In accordance with the terms
of the Trust Agreement, we hereby authorize you to liquidate all of the assets in the Trust Account on ____________, 20__ and keep the
total proceeds thereof in the Trust Account to await distribution to the Public Stockholders. The Company has selected _______________
1 as the effective date for the purpose
of determining when the Public Stockholders will be entitled to receive their share of the liquidation proceeds. You agree to be the Paying
Agent of record and, in your separate capacity as Paying Agent, agree to distribute said funds directly to the Public Stockholders in
accordance with the terms of the Trust Agreement and the Amended and Restated Certificate of Incorporation of the Company. Upon the distribution
of all the funds, net of any payments necessary for reasonable unreimbursed expenses related to liquidating the Trust Account, your obligations
under the Trust Agreement shall be terminated, except to the extent otherwise provided in Section 1(i) of the Trust Agreement.

 

	 	Very truly yours,
	 	 
	 	Mount Rainier Acquisition Corp.
	 	 
	 	By  	 
	 	 	Name:
	 	 	Title:

 

cc:       A.G.P./Alliance Global Partners

 

 

1 15 months from the closing of the Offering.

 

     
 

     

    

 

EXHIBIT C

 

[Letterhead of Company]

 

[Insert date]

 

American Stock Transfer & Trust Company, LLC

6201 15th Avenue |

Brooklyn, NY 11219

Attn: Relationship Management

 

Re:       Trust Account No.
                        Tax
Withdrawal Instruction

 

Ladies and Gentlemen:

 

Pursuant to Section 1(j)
of the Investment Management Trust Agreement between Mount Rainier Acquisition Corp. (the “Company”) and American
Stock Transfer & Trust Company, LLC (the “Trustee”), dated as of [●], 2021 (the “Trust
Agreement”), the Company hereby requests that you deliver to the Company $______________ of the interest income earned on
the Property as of the date hereof. Capitalized terms used but not defined herein shall have the meanings set forth in the Trust Agreement.

 

The Company needs such funds
to pay for the tax obligations as set forth on the attached tax return or tax statement. In accordance with the terms of the Trust Agreement,
you are hereby directed and authorized to transfer (via wire transfer) such funds promptly upon your receipt of this letter to the Company’s
operating account at:

[WIRE INSTRUCTION INFORMATION]

 

	 	Very truly yours,
	 	 
	 	Mount Rainier Acquisition Corp.
	 	 
	 	By  	 
	 	 	Name:
	 	 	Title:

 

cc:       A.G.P./Alliance Global Partners

 

     
 

     

    

 

EXHIBIT D

 

[Letterhead of Company]

 

[Insert date]

 

American Stock Transfer & Trust Company, LLC

6201 15th Avenue |

Brooklyn, NY 11219

Attn: Relationship Management

 

Re:       Trust Account No.                 Stockholder
Redemption Withdrawal Instruction

 

Gentlemen:

 

Pursuant to Section
1(k) of the Investment Management Trust Agreement between Mount Rainier Acquisition Corp. (the “Company”)
and American Stock Transfer & Trust Company, LLC (the “Trustee”), dated as of [●], 2021 (the “Trust
Agreement”), the Company hereby requests that you deliver $_____________ of the principal and interest income earned on
the Property as of the date hereof to a segregated account held by you on behalf of Public Stockholders who have properly elected to have
their shares of Common Stock that were sold by the Company in the Offering (the “Public Shares”) redeemed by
the Company as described below. Capitalized terms used but not defined herein shall have the meanings set forth in the Trust Agreement.

 

The Company needs such funds
to pay the Public Stockholders who have properly elected to have their Public Shares redeemed by the Company in connection with a stockholder
vote to approve an amendment to the Company’s Amended and Restated Certificate of Incorporation to modify the substance or timing
of the ability of Public Stockholders to seek redemption in connection with an initial Business Combination or the Company’s obligation
to redeem 100% of the Public Shares if the Company has not consummated an initial Business Combination within such time as is described
in the Company’s Amended and Restated Certificate of Incorporation or to affect provisions of the Company’s Amended and Restated
Certificate of Incorporation relating to the Company’s pre-initial Business Combination activity or related stockholder rights.
As such, you are hereby directed and authorized to transfer (via wire transfer) such funds promptly upon your receipt of this letter to
a segregated account held by you on behalf of such Public Stockholders.

 

	 	Very truly yours,
	 	 
	 	Mount Rainier Acquisition Corp.
	 	 
	 	By  	 
	 	 	Name:
	 	 	Title:

 

cc:       A.G.P./Alliance Global Partners

Source: [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00333-of-00352.parquet"}, [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00333-of-00352.parquet"}]]