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THIRD AMENDMENT TO CREDIT ADDENDUM

            THIS THIRD AMENDMENT TO CREDIT ADDENDUM (the “Amendment”) is made
effective as of May 1, 2013 (the “Effective Date”), by and between USG NEVADA
LLC, a Delaware limited liability company (“Owner”), and SAIC CONSTRUCTORS, LLC,
an Oklahoma limited liability company formerly known as Benham Constructors, LLC
(“Contractor”).

RECITALS

A.

Owner and Contractor entered into that certain Credit Addendum to Engineering,
Procurement and Construction Contract dated August 27, 2010, as amended by that
certain First Amendment to Credit Addendum dated as of May 20, 2011 and the
Second Amendment to Credit Addendum dated as of January 25, 2012 (the “Credit
Addendum”), for the construction of the Project and related construction
financing to be provided by Contractor to Owner for the construction of the
Project. All capitalized terms which are not otherwise defined herein shall have
those meanings set forth in the Credit Addendum.

    B.

As of the Effective Date, as partial payment of the indebtedness outstanding
under the Credit Addendum, Owner has (i) between February 1, 2013 and the
Effective Date, delivered cash payments in the aggregate amount of $1,000,000 to
Contractor, (ii) performed certain work on behalf of Contractor with an
aggregate value of $175,000, and (iii) delivered a loan agreement and
accompanying promissory note evidencing indebtedness to Contractor in the
principal amount of $2,000,000 duly executed by USG Nevada Holdings LLC, a
Delaware limited liability company, and a guaranty of such indebtedness by U.S.
Geothermal, Inc., an Idaho corporation (“Parent”).

    C.

Owner and Contractor desire to amend the Credit Addendum as set forth herein.

AGREEMENT

            NOW, THEREFORE, in consideration of the foregoing recitals and the
mutual covenants and agreements contained in this Amendment which are
incorporated herein, and for other good and valuable consideration, the receipt
and sufficiency of which are hereby acknowledged, Owner and Contractor hereby
agree to amend the Credit Addendum, as follows:

  1.

Payment Terms; Promissory Note. Section 1 of the Credit Addendum is hereby
deleted and superseded in its entirety and replaced with the following section:

          1.

Payment Terms; Promissory Note. Owner and Contractor agree that as of the
Effective Date Owner’s aggregate indebtedness under the EPC Contract is
$26,350,000 which amount is the total indebtedness of Owner to Contractor and
includes all principal, accrued interest, fees and all other amounts Owner owes
Contractor under the Credit Addendum (the “Indebtedness Amount”). The
Indebtedness Amount shall be payable by Owner as follows: (a) on the Effective
Date, Owner shall pay Contractor $1,350,000, which shall be applied to the
Indebtedness Amount; and (b) Owner shall execute and deliver an Amended and
Restated Promissory Note in the principal amount of $25,000,000, bearing
interest at the rate of 10.0% per annum (the “Note”). Pursuant to the terms of
the Note, Owner shall pay Contractor the amount of $300,000 on the first day of
each calendar month until November 15, 2013 (the “Maturity Date”). On the
Maturity Date, Owner shall pay Contractor all outstanding principal and accrued
interest under the Note. If Owner fails to make any such payments when due
hereunder or under the Note, the unpaid balance of the Note shall accrue
interest from the date of such failure until paid at the rate of 12.5% per
annum. Owner is currently in negotiations for a senior secured loan. Contractor
agrees to use its best efforts to support Owner in its pursuit of such loan.

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  2.

Financial Statements, Reports and Documents. Section 5.13 of the Credit Addendum
is hereby amended by adding the following as new subsection (d):

          (d)

Monthly Statements. As soon as available, and in any event within 30 days after
the end of each calendar month, copies of the unaudited balance sheet of Owner,
as of the end of such month, and the unaudited statements of income and cash
flow of Owner for such month and for the portion of the calendar year ending
with such period all in reasonable, and certified by the Chief Financial Officer
of Owner as being true and correct and as having been prepared in accordance
with GAAP consistently applied, subject to year end audit adjustments.

  3.

Form of Note. The Note contemplated by Section 1 above shall be in the form of
Exhibit A to this Amendment.

        4.

Representations and Warranties of Owner. By its execution and delivery hereof,
Owner represents and warrants that, as of the date hereof:

(a)        the representations and warranties contained in the Credit Addendum
and the other Loan Documents are true and correct in all material respects
(except that any representation or warranty that is qualified as to
“materiality” or “Material Adverse Effect” is true and correct in all respects)
on and as of the date hereof as made on and as of such date, except to the
extent that such representations and warranties specifically refer to an earlier
date, in which case they shall be true and correct as of such earlier date;

(b)        no event has occurred and is continuing which constitutes a Default
or Event of Default, nor will any Default or Event of Default result from
Owner’s execution, delivery, and performance of this Amendment; and

(c)        the execution, delivery, and performance of this Amendment by Owner
will not conflict with, result in a beach of, constitute a default under (or
with notice or the lapse of time or both could result in a breach of or
constitute a default), result in the acceleration of, create in any party the
right to accelerate, terminate, modify, or cancel, or require any notice or
consent under any agreement, contract, instrument, or other arrangement to which
Owner is a party or bound or to which any of its assets are subject.

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  5.

Representations and Warranties of Contractor. By its execution and delivery
hereof, Contractor represents and warrants that, as of the date hereof:

(a)        the representations and warranties of Contractor contained in the
Credit Addendum and the other Loan Documents are true and correct in all
material respects (except that any representation or warranty that is qualified
as to “materiality” or “Material Adverse Effect” is true and correct in all
respects) on and as of the date hereof as made on and as of such date, except to
the extent that such representations and warranties specifically refer to an
earlier date, in which case they shall be true and correct as of such earlier
date; and

(b)        the execution, delivery, and performance of this Amendment by
Contractor will not conflict with, result in a beach of, constitute a default
under (or with notice or the lapse of time or both could result in a breach of
or constitute a default), result in the acceleration of, create in any party the
right to accelerate, terminate, modify, or cancel, or require any notice or
consent under any agreement, contract, instrument, or other arrangement to which
Contractor is a party or bound or to which any of its assets are subject.

  6.

Guarantor’s Acknowledgment. By signing below, Parent (i) acknowledges, consents,
and agrees to the execution, delivery and performance by Owner of this
Amendment, (ii) acknowledges and agrees that its obligations in respect of the
Amended and Restated Change in Control Guaranty dated as of October 13, 2010
(the “Guaranty”) are not released, diminished, waived, modified, impaired, or
affected in any manner by this Amendment, or any of the provisions contemplated
herein, (iii) ratifies and confirms its obligations under the Guaranty, and (iv)
acknowledges and agrees that it has no claim or offsets against, or defenses or
counterclaims to, the Guaranty.

        7.

Miscellaneous.

(a)        Effect of Amendment. The Credit Addendum and this Amendment shall be
in full force and effect only upon the execution of this Amendment by all
parties. In the event of conflict between the terms and conditions of the Credit
Addendum and the terms and conditions of this Amendment, the terms and
conditions of this Amendment shall prevail and control. Except as expressly set
forth herein, this Amendment shall not by implication or otherwise limit,
impair, constitute a waiver of, or otherwise affect the rights or remedies of
either party under the Credit Addendum or any of the other Loan Documents, and
shall not alter, modify, amend, or in any way affect the terms, conditions,
obligations, covenants, or agreements contained in the Credit Addendum or the
other Loan Documents, all of which are hereby ratified and affirmed in all
respects and shall continue in full force and effect.

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(b)        Entire Agreement. The Credit Addendum, together with this Amendment,
embodies the entire understanding between Owner and Contractor with respect to
its subject matter and supersedes any prior agreements, negotiations, and
communications, oral or written. No subsequent agreement, representation, or
promise made by either party hereto, or by or to an employee, officer, agent or
representative of either party hereto shall be of any effect unless it is in
writing and executed by the party to be bound thereby. This Amendment and the
Credit Addendum can be changed only by an instrument in writing signed by Owner
and Contractor.

(c)        Counterparts. This Amendment may be executed in one or more
counterparts (including by facsimile or other electronic transmission), each of
which shall be deemed an original but all of which, taken together, shall
constitute one in the same Amendment.

[Signature Page Follows]

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            IN WITNESS WHEREOF, this Amendment has been executed as of the day
and year first set forth above.

OWNER: USG NEVADA LLC,   a Delaware limited liability company           By:   
___________________________________________________              Name:
___________________________________________              Title:  
___________________________________________             CONTRACTOR: SAIC
CONSTRUCTORS, LLC,   an Oklahoma limited liability company           By:  
 ___________________________________________________              Name:
___________________________________________              Title:  
___________________________________________         GUARANTOR: U.S. GEOTHERMAL,
INC.   a Delaware corporation           By:  
 ___________________________________________________              Name:
___________________________________________              Title:  
___________________________________________

[Signature Page to Third Amendment to Credit Addendum]

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EXHIBIT A

AMENDED AND RESTATED PROMISSORY NOTE

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AMENDED AND RESTATED
PROMISSORY NOTE

$25,000,000 May 1, 2013

            For value received, USG NEVADA LLC, a Delaware limited liability
company (“Borrower”), promises to pay to the order of SAIC CONSTRUCTORS, LLC, an
Oklahoma limited liability company formerly known as Benham Constructors, LLC
(“Lender”), at Lender’s principal office in Oklahoma City, Oklahoma, or at such
other place as the holder of this Amended and Restated Promissory Note (this
“Promissory Note”) may direct, in lawful money of the United States of America,
in accordance with the provisions of the Credit Addendum to Engineering,
Procurement and Construction Agreement between Borrower and Lender dated as of
August 27, 2010, as amended by the First Amendment to Credit Addendum dated as
of May 20, 2011, the Second Amendment to Credit Addendum dated as of January 25,
2012, and the Third Amendment to Credit Addendum dated as of the date hereof (as
amended, restated, extended, supplemented or otherwise modified in writing from
time to time, the “Addendum”), the principal amount of $25,000,000, together
with interest thereon at the rate of 10.0% per annum, in accordance with the
amortization schedule attached hereto as Exhibit A. Capitalized terms not
defined in this Promissory Note have the same meaning as given in the Addendum.

            1.        Payment Terms. All indebtedness evidenced by this
Promissory Note shall be due and payable in the amounts and at the times stated
in the Addendum. For the purpose of computing interest under this Promissory
Note, payments of all or any portion of the indebtedness owing under this
Promissory Note will not be deemed to have been made until such payments are
received by the holder of this Promissory Note in collected funds. Except as
otherwise provided in the Addendum, each payment received by the holder hereof
shall be applied first to unpaid costs and expenses incurred and payable under
the terms of this Promissory Note, then next to unpaid accrued interest owing on
this Promissory Note, then next with the remainder applied to the principal
unpaid balance of this Promissory Note.

            2.        Prepayment. The outstanding indebtedness owing under this
Promissory Note may be prepaid in whole or partial prepayments at any time or
from time to time without premium or penalty.

            3.        Benefits. This is the Promissory Note referred to in the
Addendum, and is issued pursuant to all the terms and provisions of the
Addendum. The holder of this Promissory Note is entitled to the benefits of the
Addendum and the Loan Documents, and may enforce the agreements contained
therein and exercise the rights provided for thereby or otherwise in respect
thereof, all in accordance with the terms thereof. Reference to the Addendum
shall not affect or impair the absolute unconditional obligation of Borrower to
pay the principal of, interest on, and any additional payment in connection
with, this Promissory Note when due.

            4.        Acceleration. Upon the occurrence of an Event of Default
under the Addendum or a default or event of default in or under any Loan
Document, the holder of this Promissory Note, at the holder’s option, may
declare immediately due and payable the entire unpaid principal balance of, and
all accrued and unpaid interest on, this Promissory Note, and exercise any or
all other rights provided in the Addendum and Security Documents, or at law or
in equity, without notice, formal demand or presentment, all of which are hereby
waived by Borrower.

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            5.        Maximum Rate. Regardless of any provision contained in
this Promissory Note or the Addendum, Lender shall never be entitled to contract
for, charge, receive, collect or apply as interest on this Promissory Note any
amount in excess of the maximum rate of interest provided under applicable
Nevada law (the “Maximum Rate”), and, in the event that the holder of the
Promissory Note ever receives, collects or applies as interest any such excess,
the amount which would be excessive interest shall be deemed to be a partial
prepayment of principal and treated hereunder as such; and, if the principal
amount of the Promissory Note is paid in full, any remaining excess shall
forthwith be paid to Borrower. In determining whether or not the interest paid
or payable under any specific contingency exceeds the Maximum Rate, Lender and
Borrower shall, to the maximum extent permitted under applicable law, (i)
characterize any non-principal payment as an expense, fee or premium rather than
as interest, (ii) exclude voluntary and mandatory prepayments and the effects
thereof, and (iii) amortize, prorate, allocate and spread the total amount of
interest throughout the entire contemplated term of the Promissory Note;
provided that, if the entire unpaid principal balance together with all accrued
interest thereon are paid and performed in full prior to the end of the full
contemplated term thereof, and if the interest received for the actual period of
existence thereof exceeds the Maximum Rate, Lender shall refund to Borrower the
amount of such excess or credit the amount of such excess against the principal
amount of the Promissory Note, and, in such event, Lender shall not be subject
to any penalties provided by any laws for contracting for, charging, taking,
reserving or receiving interest in excess of the Maximum Rate.

            6.        Right of Setoff. Upon the occurrence of an Event of
Default, Borrower grants to the holder of this Promissory Note the right to set
off against the indebtedness evidenced by or owing under this Promissory Note
any and all of such holder’s liabilities to Borrower, if any, and all money or
property in the holder’s possession held for or owed to Borrower.

            7.        Waiver. Except as otherwise expressly provided in this
Promissory Note or in the Loan Documents, Borrower and all sureties, endorsers
and guarantors of this Promissory Note (i) waive demand, presentment for
payment, notice of intention to accelerate, notice of acceleration, protest,
notice of protest and all other notices, filing of suit and diligence in
collecting this Promissory Note or enforcing any of the security herefor, (ii)
agree to any substitution, exchange or release of any such security or the
release of any party primarily or secondarily liable herefor, (iii) agree that
it will not be necessary for any holder hereof, in order to enforce payment of
this Promissory Note by such holder, to first institute suit or exhaust its
remedies against Borrower or others liable herefor, or to enforce its rights
against any security herefor, and (iv) consent to any and all extensions for any
period, renewals or postponements of time of payment of this Promissory Note or
any other indulgences with respect hereto, without notice thereof to any of
them.

            8.        Attorneys’ Fees. If this Promissory Note is collected by
legal proceedings or through a probate or bankruptcy court, or is placed in the
hands of an attorney for collection upon acceleration or after maturity, no
matter how maturity or acceleration is brought about, Borrower agrees to pay the
reasonable attorneys’ fees and all other collection costs incurred by the holder
of this Promissory Note.

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            9.        Governing Law; Venue. This Promissory Note shall be
construed in accordance with and governed by the laws of the State of Nevada.
Any action related to this Promissory Note shall be brought in any state or
federal court located in Washoe County, Nevada, and the parties submit to the
jurisdiction of such courts for such purpose.

            10.        Restatement of Note. This Promissory Note is executed and
delivered not in payment of the indebtedness evidenced by the Promissory Note
dated August 27, 2010 in the original principal amount of $24,553,000 executed
and delivered by Borrower, but to evidence and restate the amended terms of the
original indebtedness. This Note is not a novation.

[Signature Page Follows]

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            IN WITNESS WHEREOF, Borrower has executed this Amended and Restated
Promissory Note as of the date and year first above written.

USG NEVADA LLC,
a Delaware limited liability company

  By:   ___________________________________________________            Name:
______________________________________________            Title:  
______________________________________________

[Signature Page to Amended and Restated Promissory Note]

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EXHIBIT A

AMORTIZATION SCHEDULE

Principal   Rate   Term Payment 25,000,000   10%   143 $300,000            
PAYMENT MONTHLY CUM.   CUM.   NUMBER PRINCIPAL  PRINCIPAL INTEREST INTEREST
PAYMENT     $25,000,000        1-May-13 91,667  24,908,333 208,333   208,333
300,000 1-Jun-13   92,431  24,815,903 207,569   415,903 300,000 1-Jul-13   
93,201  24,722,702 206,799   622,702 300,000 1-Aug-13  93,977  24,628,724
206,023   828,724 300,000 1-Sep-13  94,761  24,533,964 205,239 1,033,964 300,000
1-Oct-13  95,550  24,438,414 204,450 1,238,414 300,000 1-Nov-13 48,173
 24,390,240 101,827 1,340,240 150,000

Note:

Last Payment on Nov 1 is one half a month's payment for 15 days to the end of
the Note's term at Nov 15, 2013 when the remaining principal is due in full.

[Signature Page to Amended and Restated Promissory Note]

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