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                                                                    Exhibit 4.04


THIS SECURITY IS A GLOBAL SECURITY AS REFERRED TO IN THE INDENTURE HEREINAFTER
REFERENCED. UNLESS AND UNTIL IT IS EXCHANGED IN WHOLE OR IN PART FOR THE
INDIVIDUAL SECURITIES REPRESENTED HEREBY, THIS GLOBAL SECURITY MAY NOT BE
TRANSFERRED EXCEPT AS A WHOLE BY THE DEPOSITARY TO A NOMINEE OF THE DEPOSITARY
OR BY A NOMINEE OF THE DEPOSITARY TO THE DEPOSITARY OR ANOTHER NOMINEE OF THE
DEPOSITARY OR BY THE DEPOSITARY OR ANY SUCH NOMINEE TO A SUCCESSOR DEPOSITARY OR
A NOMINEE OF SUCH SUCCESSOR DEPOSITARY.

UNLESS THIS CERTIFICATE IS PRESENTED BY AN AUTHORIZED REPRESENTATIVE OF THE
DEPOSITORY TRUST COMPANY (55 WATER STREET, NEW YORK, NEW YORK) TO THE ISSUER OR
ITS AGENT FOR REGISTRATION OF TRANSFER, EXCHANGE OR PAYMENT, AND ANY CERTIFICATE
ISSUED IS REGISTERED IN THE NAME OF CEDE & CO. OR SUCH OTHER NAME AS REQUESTED
BY AN AUTHORIZED REPRESENTATIVE OF THE DEPOSITORY TRUST COMPANY AND ANY PAYMENT
IS MADE TO CEDE & CO., ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR
OTHERWISE BY OR TO ANY PERSON IS WRONGFUL SINCE THE REGISTERED OWNER HEREOF,
CEDE & CO., HAS AN INTEREST HEREIN.


REGISTERED        PRINCIPAL AMOUNT
NO. FLR-__

$_________

CUSIP No.:_________


                               QUESTAR GAS COMPANY
                           MEDIUM-TERM NOTE, SERIES D
                                 (FLOATING RATE)

Original Issue Date:                 Minimum Rate:
Stated Maturity:                     Maximum Rate:
Interest Payment Date(s):            Interest Reset Dates:
Regular Record Date(s):              Interest Reset Period:
Base Rate(s):                        Interest Determination Date:
Default Rate:                        Sinking Fund/Repayment Provision:
Index Maturity:                      Optional Repayment Date:
Initial Interest Rate:               Optional Redemption: see below
Spread:                              Redemption Percentage: see below
Spread Multiplier:                   Annual Redemption Percentage: see below
Interest Category:                   Redemption Commencement Date: see below
Authorized Determination:            Redemption Date: see below

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Specified Currency:                  Redemption Price: see below
Calculation Agent:
Exchange Rate Agent:
Other Provisions:

                  The Redemption Price (if applicable) shall initially be the
Redemption Percentage of the principal amount of this Note to be redeemed and
shall decline (but not below par) at each anniversary of the Redemption
Commencement Date by the Annual Redemption Percentage of the principal amount to
be redeemed until the Redemption Price is 100% of such principal amount. "N/A"
as used herein means "Not Applicable". "A/S" as used herein means "As stated in
this Note".

                  QUESTAR GAS COMPANY, a corporation duly organized and existing
under the laws of the State of Utah (herein called the "Company", which term
includes any successor corporation under the Indenture hereinafter referred to),
for value received, hereby promises to pay to CEDE & CO., or registered assigns,
the principal sum of _________________________________________ DOLLARS
($______________) at Stated Maturity as specified above (except to the extent
redeemed or repaid prior to the Stated Maturity), and to pay interest thereon
from the Original Issue Date specified above or from the most recent Interest
Payment Date (subject to the provisions below) to which interest has been paid
or duly provided for, periodically on each Interest Payment Date, commencing
with the first such Interest Payment Date next succeeding the Original Issue
Date specified above, and at Stated Maturity (the date on each such Stated
Maturity, Redemption Date, and Optional Repayment Date and the date on which
principal or an installment of principal is due and payable by declaration of
acceleration pursuant to the Indenture being referred to hereinafter as a
"Maturity" with respect to principal payable on such date), at the Interest to
be determined in accordance with the provisions below, depending on the Base
Rate(s) shown above (the "Floating Interest Rate"), until the principal hereof
is paid or made available for payment; PROVIDED, that if such Original Issue
Date is after a Regular Record Date and before the Interest Payment Date
immediately following such Regular Record Date, interest payments will commence
on the second Interest Payment Date following the Original Issue Date. The
interest so payable, and punctually paid or duly provided for, on any Interest
Payment Date (except at Maturity) will, as provided in the Indenture, be paid to
the Person in whose name this Note (or one or more Notes which are Predecessor
Securities) is registered at the close of business on the Regular Record Date
next preceding such Interest Payment Date. Any such interest which is payable,
but not so punctually paid or duly provided for on any Interest Payment Date,
will forthwith cease to be payable to the Holder on such Regular Record Date and
may either be


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paid to the Person in whose name this Note (or one or more Notes which are
Predecessor Securities) is registered at the close of business on a Special
Record Date for the payment of such Defaulted Interest to be fixed by the
Trustee, notice whereof shall be given to the Holder of this Note not less
than 10 days prior to such Special Record Date, or be paid at any time in any
other lawful manner not inconsistent with the requirements of any securities
exchange on which the Notes of this series may be listed, upon such notice as
may be required by such exchange, all as more fully provided in the
Indenture. Reference herein to "this Note", "hereof", "herein" and comparable
terms shall include an Addendum hereto if an Addendum is specified above.

                  Any provision contained herein with respect to the calculation
of the rate of interest applicable to this Note, its payment dates or any other
matter relating hereto may be modified as specified in an Addendum relating
hereto if so specified above.

                  This Note is one of a duly authorized series of debt
securities of the Company (herein called the "Securities"), and the series
thereof to which this Note belongs, being issued and to be issued under an
Indenture, dated as of May 1, 1992 (herein called the "Indenture"), between the
Company and Wells Fargo Bank Northwest, National Association (f/k/a First
Security Bank, N.A.), as successor trustee to Citibank, N.A. (herein called the
"Trustee", which term includes any successor trustee under the Indenture), and
reference is hereby made to the Indenture and all indentures supplemental
thereto for a statement of the respective rights, limitations of rights, duties
and immunities thereunder of the Company, the Trustee and the Holders of the
Notes and of the terms upon which the Notes are, and are to be, authenticated
and delivered. This Note is one of the series of Securities designated as
"Medium-Term Notes, Series D." The Notes may be issued from time to time at
varying maturities, interest rates and other terms and in an aggregate principal
amount up to $100,000,000, which amount may be increased if duly authorized by
the Company.

                  If this Note is a definitive Note, payments of the principal,
premium, if any, and interest payable at Maturity on this Note will be made in
immediately available funds at the Corporate Trust Office of the Trustee in Salt
Lake City, Utah or at such other place as the Company may designate, provided
that this Note is presented to the Trustee in time for the Trustee to make such
payments in such funds in accordance with its normal procedures. Interest (other
than interest payable at Maturity) will be paid by check mailed to the address
of the Person entitled thereto as it appears in the Security Register as of the
Regular Record Date or, at the option of


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the Company, by wire transfer to an account maintained by such Person with a
bank located within the United States; PROVIDED, HOWEVER, that if Holder of
this Note holds $10,000,000 or more in aggregate principal amount, such
Holder may be entitled to receive payments of principal, premium, if any, and
interest by wire transfer to an account maintained by such Holder with a bank
located in the United States if an appropriate written request has been
received by the Trustee prior to the Regular Record Date in respect of any
interest payment, or the date which is fifteen days before the Stated
Maturity of the Note, as the case may be.

                  If this Note is a Global Security representing Book-Entry
Securities, payments of the principal of, premium, if any, and interest on the
Note will be made by check or by wire transfer to an account maintained by the
Depositary for such purpose.

                  This Note will be redeemable as a whole or in part, at the
option of the Company at any time, at a Redemption Price equal to the greater of
(i) 100% of its principal amount and (ii) the sum of the present values of the
remaining scheduled payments of principal and interest thereon discounted to the
Redemption Date on a semiannual basis (assuming a 360-day year consisting of
twelve 30-day months) at the Treasury Rate plus [ ] basis points, plus in each
case accrued and unpaid interest thereon to the date of redemption.

                  "Treasury Rate" means, with respect to any Redemption Date,
the rate per annum equal to the semiannual equivalent yield to maturity or
interpolated (on a day count basis) of the Comparable Treasury Issue, assuming a
price for the Comparable Treasury Issue (expressed as a percentage of its
principal amount) equal to the Comparable Treasury Price for such Redemption
Date.

                  "Comparable Treasury Issue" means the United States Treasury
security or securities selected by an Independent Investment Banker as having a
maturity or interpolated (on a day count basis) comparable to the remaining term
of this Note that would be utilized, at the time of selection and in accordance
with customary financial practice, in pricing new issues of corporate debt
securities of a comparable maturity to the remaining term of this Note.
"Independent Investment Banker" means one of the Reference Treasury Dealers
appointed by the Trustee after consultation with the Company.

                  "Comparable Treasury Price" means, with respect to any
Redemption Date, (i) the average of the Reference Treasury Dealer Quotations for
such Redemption Date, after excluding the highest and lowest such Reference
Treasury Dealer


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Quotations, or (ii) if the Trustee obtains fewer than four such Reference
Treasury Dealer Quotations, the average of all such quotations. "Reference
Treasury Dealer Quotations" means, with respect to each Reference Treasury
Dealer and any redemption date, the average, as determined by the Trustee, of
the bid and asked prices for the Comparable Treasury Issue (expressed in each
case as a percentage of its principal amount) quoted in writing to the
Trustee by such Reference Treasury Dealer at 3:30 p.m. New York time on the
third business day preceding such Redemption Date.

                  "Reference Treasury Dealer" means each of Merrill Lynch,
Pierce, Fenner & Smith Incorporated, Banc One Capital Markets, Inc. and U.S.
Bancorp Piper Jaffray Inc. and their respective successors; provided, however,
that if any of the foregoing or their affiliates shall cease to be a primary
U.S. Government securities dealer in The City of New York (a "Primary Treasury
Dealer"), the Company shall substitute therefor another Primary Treasury Dealer.

                  Notice of any redemption will be mailed at least 30 days but
not more than 60 days before the Redemption Date to the Holder of this Note.

                  Unless the Company defaults in payment of the Redemption
Price, on and after the Redemption Date interest will cease to accrue on this
Note or portions thereof called for redemption.

                  In the event of redemption of this Note in part only, a new
Note for the unredeemed portion hereof will be issued in the name of the Holder
hereof upon the cancellation hereof.

                  If so provided on the first page of this Note, this Note will
be subject to repayment at the option of the Holder hereof on the Optional
Repayment Date, if any, indicated on the first page hereof. If no Optional
Repayment Date is set forth on the first page hereof, this Note will not be
repayable at the option of the Holder prior to Stated Maturity. On any Optional
Repayment Date, this Note will be repayable in whole or in part in increments of
$1,000 at the option of the Holder hereof at a price equal to 100% of the
principal amount to be repaid, together with interest thereon payable to the
Optional Repayment Date, on notice in the form entitled "Option to Elect
Repayment" below, duly completed, given together with this Note by such Holder
to the Company not more than 60 nor less than 30 days prior to the Optional
Repayment Date. In the event of repayment of this Note in part only, a new Note
for the portion hereof not repaid will be issued in the name of the Holder
hereof upon the surrender hereof. Exercise of such repayment option by the
Holder shall be irrevocable.


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                  The "Floating Interest Rate" on this Note will be calculated
by reference to the Base Rate(s), as specified on the first page hereof, (a)
plus or minus the Spread, if any, and/or (b) multiplied by the Spread
Multiplier, if any. The Base Rate may be one or more of: (a) the Commercial
Paper Rate, (b) the Federal Funds Rate, (c) LIBOR, (d) the Prime Rate, (e) the
Treasury Rate or (f) such other interest rate formula as is set forth on the
first page hereof. The "Index Maturity" is the period to maturity of the
instrument or obligation with respect to which the related Base Rate or Rates
are calculated. Except as otherwise provided herein, all percentages resulting
from any calculation will be rounded out to the nearest one hundred-thousandth
of a percentage point (with five one-millionths of a percentage point rounded
upward), and all dollar amounts used in or resulting from such calculation will
be rounded to the nearest cent (with one-half cent being rounded upward).

                  Notwithstanding the foregoing, if this Note is designated
above as having an Addendum attached, the Note shall bear interest in accordance
with the terms described in such Addendum.

                  Unless otherwise specified on the first page hereof, the
"Regular Record Date" with respect to this Note shall be the fifteenth calendar
day immediately preceding the related Interest Payment Date or Dates, whether or
not such date shall be a Business Day, and interest will be payable, in the case
of Notes which reset daily, each Business Day, in the case of Notes which reset
weekly, on Wednesday of each week (with the exception of weekly reset Floating
Rate Notes as to which the Treasury Rate is an applicable Base Rate, which will
reset Tuesday of each week, except as described below), in the case of Notes
which reset monthly, on the third Wednesday of each month, in the case of Notes
which reset quarterly, on the third Wednesday of March, June, September and
December of each year, in the case of Notes which reset semi-annually, on the
third Wednesday of the two months of each year specified on the first page
hereof, and in the case of Notes which reset annually, on the third Wednesday of
the month specified on the first page hereof (each an "Interest Payment Date");
and, in each case, at Maturity.

                  Payments of Interest with respect to any Interest Payment Date
will include interest accrued to but excluding such Interest Payment Date.
Accrued interest is calculated by multiplying the face amount of this Note by an
accrued interest factor. Such accrued interest factor is computed by adding the
interest factor calculated for each day from the later of the Original Issue
Date, or from the last date to which interest has been paid or duly provided
for, to the date for which accrued interest is being calculated. The interest
factor (expressed as a decimal rounded to


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the nearest one hundred-thousandth of a percentage point) for each such day
is computed by dividing the interest rate (expressed as a decimal rounded to
the nearest one-hundred-thousandth of a percentage point) applicable to such
day by 360, in the case of Commercial Paper Rate Notes, Federal Funds Rate
Notes, LIBOR Notes, or Prime Rate Notes or by the actual number of days in
the year, in the case of Treasury Rate Notes. The interest factor for
Floating Rate Notes for which the interest rate is calculated with reference
to two or more Base Rates will be calculated in each period in the same
manner as if only the lowest of the applicable Base Rates applied. If any
Interest Payment Date for this Note falls on a day that is not a Business Day
with respect to this Note, such Interest Payment Date for this Note will be
the following day that is a Business Day for this Note, except that, in the
case of a LIBOR Note (or a Note for which LIBOR is the applicable Base Rate),
if such Business Day is in the next succeeding calendar month, such Interest
Payment Date will be the immediately preceding day that is a Business Day for
this Note. If the Maturity of this Note falls on a day that is not a Business
Day with respect to this Note, the payment of principal, premium, if any, and
interest will be made on the next succeeding Business Day, and no interest on
such payment shall accrue for the period from and after Maturity. Unless
otherwise specified on the first page hereof or in an Addendum hereto,
"Business Day" means any day that is not a Saturday or Sunday and that in the
Place of Payment is not a day on which banking institutions are authorized or
obligated by law or executive order to close, and, with respect to any LIBOR
Note, is a London Business Day. "London Business Day" means any day on which
dealings in deposits in United States dollars are transacted in the London
interbank market.

                  Except as provided on the first page hereof, the rate of
interest on this Note will be reset daily, weekly, monthly, quarterly,
semi-annually or annually (each an "Interest Reset Date"), as specified on the
first page hereof. Except as provided on the first page hereof, if this Note
resets daily, the Interest Reset Date will be each Business Day, if this Note
resets weekly, the Interest Reset Date will be on Wednesday of each week (with
the exception of weekly reset Floating Rate Notes as to which the Treasury Rate
is an applicable Base Rate, which will reset on Tuesday of each week, except as
described below), if this Note resets monthly, the Interest Reset Date will be
the third Wednesday of each month, if this Note resets quarterly, the Interest
Reset Date will be the third Wednesday of each March, June, September and
December of each year, if this Note resets semi-annually the Interest Reset Date
will be the third Wednesday of each of the two months of each year specified on
the first page hereof, and if this Note resets annually, the Interest Reset Date
will be the third Wednesday of the month of each year as specified on the first
page hereof, PROVIDED, HOWEVER, that (a) the interest rate in effect from the
Original Issue Date to the first Interest Reset Date will be the Initial
Interest Rate (as set forth on the first page


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hereof), and (b) the interest rate in effect for the ten calendar days
immediately prior to Maturity will be the interest rate in effect on the
tenth calendar day preceding such Maturity. If any Interest Reset Date would
otherwise be a day that is not a Business Day, such Interest Reset Date shall
be the next succeeding Business Day (or, in the case of a LIBOR Note or a
Note for which LIBOR is an applicable Base Rate, if such Business Day falls
in the next calendar month, such Interest Reset Date shall be the last
Business Day in the preceding month).

                  The interest rate applicable to each Interest Reset Period
commencing on the Interest Reset Date or Dates with respect to such Interest
Reset Period will be the rate determined as of the applicable "Interest
Determination Date." The Interest Determination Date with respect to the
Commercial Paper Rate, the Federal Funds Rate and the Prime Rate will be the
second Business Day preceding each Interest Reset Date. The Interest
Determination Date with respect to LIBOR will be the second London Business Day
preceding each Interest Reset Date. With respect to the Treasury Rate, the
Interest Determination Date will be the day in the week in which the Interest
Reset Date falls on which day Treasury Bills are normally auctioned (Treasury
Bills are normally sold at auction on Monday of each week, unless that day is a
legal holiday, in which case the auction is normally held on the following
Tuesday, except that such auction may be held on the preceding Friday);
PROVIDED, HOWEVER, that if, as a result of a legal holiday, an auction is held
on the Friday of the week preceding the Interest Reset Date, the related
Interest Determination Date shall be such preceding Friday; and PROVIDED,
FURTHER, that if an auction shall fall on any Interest Reset Date, then the
related Interest Reset Date shall instead be the first Business Day immediately
following such auction. If the interest rate of this Note is determined with
reference to two or more Base Rates, the Interest Determination Date will be the
first Business Day which is at least two Business Days prior to such Interest
Reset Date on which each Base Rate shall be determinable. Each Base Rate shall
be determined and compared on such date, and the applicable interest rate shall
take effect on the related Interest Reset Date.

                  The Calculation Agent (which shall be the Trustee unless
otherwise specified on the first page hereof and which may be changed by the
Company from time to time) shall calculate the Floating Interest Rate on this
Note on or before each Calculation Date and, upon request, provide to holders
the Floating Interest Rate then in effect and, if different, the interest rate
which will become effective as a result of a determination made for the next
succeeding Interest Reset Date with respect to this Note. The Calculation
Agent's determination of any Floating Interest Rate will be final and binding in
the absence of manifest error. Unless otherwise specified on the first page
hereof or in an Addendum hereto, the "Calculation Date", where applica-


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ble, pertaining to any Interest Determination Date will be the earlier of (i)
the tenth calendar day after such Interest Determination Date, or if any such
day is not a Business Day, the next succeeding Business Day or (ii) the
Business Day immediately preceding the applicable Interest Payment Date or
Maturity, as the case may be.

                  Notwithstanding the other provisions herein, the Floating
Interest Rate hereon which may accrue during any interest period shall not be
greater than the Maximum Interest Rate, if any, or less than the Minimum
Interest Rate, if any, shown on the first page hereof and, in addition, the
Floating Interest Rate shall in no event be higher than the maximum rate
permitted by New York law, as the same may be modified by United States law of
general application.

DETERMINATION OF COMMERCIAL PAPER RATE.

                  The "Commercial Paper Rate" will be determined by the
Calculation Agent in accordance with the following provisions:

                  "Commercial Paper Rate" means, with respect to any Interest
Determination Date relating to a Commercial Paper Rate Note or to any Note for
which the Commercial Paper Rate is one of the Base Rates (a "Commercial Paper
Rate Interest Determination Date"), the Money Market Yield (as defined below) on
such date of the rate for commercial paper having the Index Maturity specified
on the first page hereof as published by the Board of Governors of the Federal
Reserve System in "Statistical Release H.15(519), Selected Interest Rates" or
any successor publication ("H.15 (519)") under the heading "Commercial
Paper--Nonfinancial" or, if unavailable, under such other heading representing
commercial paper issued by non-financial entities whose bond rating is "AA", or
the equivalent, from a nationally recognized statistical rating organization. In
the event that such rate is not published by 3:00 P.M., New York City time, on
the Calculation Date pertaining to such Commercial Paper Rate Interest
Determination Date, then the Commercial Paper Rate shall be the Money Market
Yield on such Commercial Paper Rate Interest Determination Date of the rate for
commercial paper having the Index Maturity specified on the first page hereof as
published by the Federal Reserve Bank of New York in its daily statistical
release "Composite 3:30 P.M. Quotations for U.S. Governmental Securities" or any
successor publication ("Composite Quotations") under the heading "Commercial
Paper" (with an Index Maturity of one month or three months being deemed to be
equivalent to an Index Maturity of thirty days or ninety days, respectively). If
such rate is not published in either H.15 (519) or Composite Quotations by 3:00
P.M., New York City time, on such Calculation Date, then the Commercial Paper
Rate will be calculated by the Calculation Agent and will


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be the Money Market Yield of the arithmetic mean of the offered rates, as of
approximately 11:00 A.M., New York City time, on such Commercial Paper Rate
Interest Determination Date, of three leading dealers of commercial paper in
The City of New York (which may include one or more of the Agents or their
affiliates) selected by the Calculation Agent (after consultation with the
Company) for commercial paper having the specified Index Maturity placed for
a nonfinancial issuer whose bond rating is "AA," or the equivalent, from a
nationally recognized statistical rating organization; PROVIDED, HOWEVER,
that if the dealers selected as aforesaid by the Calculation Agent are not
quoting as mentioned in this sentence, the Commercial Paper Rate determined
as of such Commercial Paper Interest Determination Date will be the
Commercial Paper Rate in effect on such Commercial Paper Rate Interest
Determination Date.

                  "Money Market Yield" shall be a yield (expressed as a
percentage) calculated in accordance with the following formula:

                                            D x 360
         Money Market Yield = [----------------] x 100
                                         360 - (DxM)

where "D" refers to the applicable per annum rate for commercial paper quoted on
a bank discount basis and expressed as a decimal and "M" refers to the actual
number of days in the interest period for which interest is being calculated.

DETERMINATION OF FEDERAL FUNDS RATE.

                  The "Federal Funds Rate" will be determined by the Calculation
Agent in accordance with the following provisions:

                  "Federal Funds Rate" means, with respect to any Interest
Determination Date relating to a Federal Funds Rate Note or a Floating Rate Note
for which the interest rate is determined with reference to the Federal Funds
Rate (a "Federal Funds Rate Interest Determination Date"), the rate on such date
for United States dollar federal funds as published in H.15(519) under the
heading "Federal Funds (Effective)" or, if not published by 3:00 P.M., New York
City time, on the related Calculation Date, the rate on such Federal Funds Rate
Interest Determination Date as published in Composite Quotations under the
heading "Federal Funds/Effective Rate." If such rate is not published in either
H.15(519) or Composite Quotations by 3:00 P.M., New York City time, on the
related Calculation Date, then the Federal Funds Rate on such Federal Funds Rate
Interest Determination Date will be calcu-


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lated by the Calculation Agent and will be the arithmetic mean of the rates
for the last transaction in overnight Untied States dollar federal funds
arranged by three leading brokers of federal funds transactions in The City
of New York (which may include the Agents or their affiliates) selected by
the Calculation Agent prior to 9:00 A.M., New York City time, on such Federal
Funds Rate Interest Determination Date; provided, however, that if the
brokers so selected by the Calculation Agent are not quoting as mentioned in
this sentence, the Federal Funds Rate determined as of such Federal Funds
Rate Interest Determination Date will be the Federal Funds Rate in effect on
such Federal Funds Rate Interest Determination Date.

DETERMINATION OF LIBOR.

                  "LIBOR" will be determined by the Calculation Agent in
accordance with the following provisions:

                  (i) With respect to an Interest Determination Date relating to
a LIBOR Note or any Floating Rate Note for which LIBOR is an applicable Base
Rate (a "LIBOR Interest Determination Date"), either, as specified on the first
page hereof: (a) the arithmetic mean of the offered rates for deposits in U.S.
dollars for the period of the Index Maturity specified on the first page hereof,
commencing on the second London Business Day immediately following such LIBOR
Interest Determination Date, which appear on the Reuters Screen LIBO Page as of
11:00 A.M., London time, on the LIBOR Interest Determination Date, if at least
two such offered rates appear on the Reuters Screen LIBO Page ("LIBOR Reuters"),
or (b) the rate for deposits in U.S. dollars having the Index Maturity
designated on the first page hereof, commencing on the second London Business
Day immediately following that LIBOR Interest Determination Date, that appears
on the Telerate Page 3750 as of 11:00 A.M., London time, on that LIBOR Interest
Determination Date ("LIBOR Telerate"). Unless otherwise indicated on the first
page hereof, "Reuters Screen LIBO Page" means the display designated as Page
"LIBO" on the Reuters Monitor Money Rate Service (or such other page as may
replace the LIBO page on that service for the purpose of displaying London
interbank offered rates of major banks). "Telerate Page 3750" means the display
designated as page "3750" on the Telerate Service (or such other page as may
replace the 3750 page on that service or such other service or services as may
be nominated by the British Bankers' Association for the purpose of displaying
London interbank offered rates for U.S. dollar deposits). If neither LIBOR
Reuters nor LIBOR Telerate is specified on the first page hereof, LIBOR will be
determined as if LIBOR Telerate had been specified. If fewer than two offered
rates appear on the Reuters Screen LIBO Page, or if no rate appears on the
Telerate Page 3750, as applicable, LIBOR in respect of that LIBOR Interest


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Determination Date will be determined as if the parties had specified the rate
described in (ii) below.

                  (ii) With respect to a LIBOR Interest Determination Date on
which fewer than two offered rates appear on the Reuters Screen LIBO Page, as
described in (i)(a) above, or on which no rate appears on the Telerate Page
3750, as specified in (i)(b) above, as applicable, LIBOR will be determined on
the basis of the rates at which deposits in U.S. dollars having the Index
Maturity designated on the first page hereof are offered at approximately 11:00
A.M., London time, on such LIBOR Interest Determination Date by four major banks
("Reference Banks") in the London interbank market selected by the Calculation
Agent (after consultation with the Company) to prime banks in the London
interbank market commencing on the second London Business Day immediately
following such LIBOR Interest Determination Date and in a principal amount of
not less than U.S. $1,000,000 that is representative for a single transaction in
such market at such time. The Calculation Agent will request the principal
London office of each of the Reference Banks to provide a quotation of its rate.
If at least two such quotations are provided, LIBOR for such LIBOR Interest
Determination Date will be the arithmetic mean of such quotations. If fewer than
two quotations are provided, LIBOR for such LIBOR Interest Determination Date
will be the arithmetic mean of the rates quoted at approximately 11:00 a.m., New
York City time, on such LIBOR Interest Determination Date by three major banks
(which may include the Agents or their affiliates) in The City of New York
selected by the Calculation Agent (after consultation with the Company) for
loans in U.S. dollars to leading European banks having the specified Index
Maturity designated on the first page hereof commencing on the second London
Business Day immediately following such LIBOR Interest Determination Date and in
a principal amount equal to an amount of not less than U.S. $1,000,000 that is
representative for a single transaction in such market at such time; PROVIDED,
HOWEVER, that if the banks selected as aforesaid by the Calculation Agent are
not quoting as mentioned in this sentence, LIBOR determined as of such LIBOR
Determination Date will be LIBOR then in effect on such LIBOR Interest
Determination Date.

DETERMINATION OF PRIME RATE.

                  The "Prime Rate" will be determined by the Calculation Agent
in accordance with the following provisions:

                  "Prime Rate" means, with respect to any Interest Determination
Date relating to a Prime Rate Note or a Floating Rate Note for which the
interest rate is determined with reference to the Prime Rate (a "Prime Rate
Interest Determination


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Date"), the rate on such date as such rate is published in H.15(519) under
the heading "Bank Prime Loan." If such rate is not published prior to 3:00 P.M.,
New York City time, on the related Calculation Date, then the Prime Rate
shall be the arithmetic mean of the rates of interest publicly announced by
each bank that appears on the Reuters Screen USPRIME1 Page (as hereinafter
defined) as such bank's prime rate or base lending rate as in effect for such
Prime Rate Interest Determination Date. If fewer than four such rates appear
on the Reuters Screen USPRIME1 Page for such Prime Rate Interest
Determination Date, then the Prime Rate shall be the arithmetic mean of the
prime rates or base lending rates quoted on the basis of the actual number of
days in the year divided by a 360-day year as of the close of business on
such Prime Rate Interest Determination Date by four major money center banks
(which may include affiliates of the Agents) in The City of New York selected
by the Calculation Agent. If fewer than four such quotations are so provided,
then the Prime Rate shall be the arithmetic mean of four prime rates quoted
on the basis of the actual number of days in the year divided by a 360-day
year as of the close of business on such Prime Rate Interest Determination
Date as furnished in The City of New York by the major money center banks, if
any, that have provided such quotations and by a reasonable number of
substitute banks or trust companies (which may include affiliates of the
Agents) to obtain four such prime rate quotations, provided such substitute
banks or trust companies are organized and doing business under the laws of
the United States, or any State thereof, each having total equity capital of
at least $500 million and being subject to supervision or examination by
Federal or State authority.

         "Reuters Screen USPRIME1 Page" means the display on the Reuter Monitor
Money Rates Service (or any successor service) on the "USPRIME1" page (or such
other page as may replace the USPRIME1 page on such service) for the purpose of
displaying prime rates or base lending rates of major United States banks.

DETERMINATION OF TREASURY RATE.

                  The "Treasury Rate" will be determined by the Calculation
Agent in accordance with the following provisions:

                  "Treasury Rate" means, with respect to any Interest
Determination Date relating to a Treasury Rate Note or any Note for which the
interest rate is determined by reference to the Treasury Rate (a "Treasury Rate
Interest Determination Date"), the rate applicable to the most recent auction of
direct obligations of the United States ("Treasury Bills") having the Index
Maturity specified on the first page


                                       13

<Page>

hereof, as such rate is published in H.15(519) under the heading "Treasury
Bills -- auction average (investment)" or, if not published by 3:00 P.M., New
York City time, on the Calculation Date pertaining to such Treasury Rate
Interest Determination Date, the auction average rate (expressed as a bond
equivalent on the basis of a year of 365 or 366 days, as applicable, and
applied on a daily basis) as otherwise announced by the United States
Department of the Treasury. In the event that the results of the auction of
Treasury Bills having the specified Index Maturity are not reported as
provided by 3:00 P.M., New York City time, on such Calculation Date, or if no
such auction is held in a particular week, then the Treasury Rate shall be
calculated by the Calculation Agent and shall be a yield to maturity
(expressed as a bond equivalent on the basis of a year of 365 days or 366
days, as applicable, and applied on a daily basis) of the arithmetic mean of
the secondary market bid rates, as of approximately 3:30 P.M., New York City
time on such Treasury Rate Interest Determination Date, of three leading
primary United States government securities dealers (which may include one or
more of the Agents or their affiliates) selected by the Calculation Agent
(after consultation with the Company), for the issue of Treasury Bills with a
remaining maturity closest to the specified Index Maturity; PROVIDED,
HOWEVER, that if the dealers selected as aforesaid by the Calculation Agent
are not quoting as mentioned in this sentence, the Treasury Rate determined
as of such Treasury Rate Interest Determination Date will be the Treasury
Rate in effect on such Treasury Rate Interest Determination Date.

                  If an Event of Default with respect to the Notes shall occur
and be continuing, the principal of all of the Notes may be declared due and
payable in the manner and with the effect provided in the Indenture.

                  The Notes are subject to satisfaction, discharge and
defeasance as provided in Section 403 of the Indenture.

                  The Indenture permits, with certain exceptions as therein
provided, the amendment thereof and the modification of the rights and
obligations of the Company and the rights of the Holders of the Securities of
each series to be affected under the Indenture at any time by the Company and
the Trustee with the consent of the Holders of a majority in principal amount of
the Securities at the time Outstanding or, in the case less than all of the
several series of Securities are affected, the holders of a majority in
aggregate principal amount of the Securities at the time Outstanding of each
series to be affected. The Indenture also contains provisions permitting the
Holders of specified percentages in aggregate principal amount of the Securities
of each series at the time Outstanding, on behalf of the Holders of all
Securities of such series, to waive compliance by the Company with certain
provi-


                                       14

<Page>

sions of the Indenture and certain past defaults under the Indenture and
their consequences. Any such consent or waiver by the Holder of this Note
shall be conclusive and binding upon such Holder and upon such future Holders
of this Note and of any Note issued upon the registration of transfer hereof
or in exchange herefor or in lieu hereof, whether or not notation of such
consent or waiver is made upon this Note.

                  No reference herein to the Indenture and no provision of this
Note or of the Indenture shall alter or impair the obligation of the Company,
which is absolute and unconditional, to pay the principal of, premium, if any,
and interest on this Note at the times, place and rate, and in the coin or
currency, herein prescribed.

                  As provided in the Indenture and subject to certain
limitations therein set forth, the transfer of this Note is registrable in the
Security Register, upon surrender of this Note for registration of transfer at
the office or agency of the Company in Salt Lake City, Utah, or at such other
place as the Company may designate from time to time, duly endorsed by, or
accompanied by a written instrument of transfer in form satisfactory to the
Company and the Security Register duly executed by, the Holder hereof or his
attorney duly authorized in writing, and thereupon one or more new Notes, of
authorized denominations and for the same aggregate principal amount, will be
issued to the designated transferee or transferees.

                  The Notes are issuable in registered form without coupons in
minimum denominations of $1,000 or any amount in excess thereof that is an
integral multiple of $1,000. As provided in the Indenture and subject to certain
limitations therein set forth, Notes are exchangeable for a like aggregate
principal amount of Notes of different authorized denominations, as requested by
the Holder surrendering the same.

                  No service charge shall be made for any such registration of
transfer or exchange, but the Company may require payment of a sum sufficient to
cover any tax or other governmental charge payable in connection therewith.

                  Prior to due presentment of this Note for registration of
transfer, the Company, the Trustee and any agent of the Company or the Trustee
may treat the Person in whose name this Note is registered as the owner hereof
for all purposes, whether or not this Note be overdue, and neither the Company,
the Trustee nor any such agent shall be affected by notice to the contrary.

                  All terms used in this Note which are defined in the Indenture
shall have the meaning assigned to them in the Indenture.


                                       15

<Page>

                  THE INDENTURE AND THE NOTES, INCLUDING THIS NOTE, SHALL BE
GOVERNED BY AND CONSTRUED IN ACCORDANCE WITH THE LAWS OF THE STATE OF NEW YORK
APPLICABLE TO AGREEMENTS MADE AND TO BE PERFORMED IN SUCH STATE.

                  Unless the certificate of authentication hereon has been
executed by Wells Fargo Bank Northwest, National Association (f/k/a First
Security Bank, N.A.), the Trustee under the Indenture, or its successor
thereunder, by the manual signature of one of its authorized officers, this Note
shall not be entitled to any benefit under the Indenture or be valid or
obligatory for any purpose.


                                       16

<Page>

                  IN WITNESS WHEREOF, the Company has caused this instrument to
be duly executed, manually or in facsimile, and a facsimile of its corporate
seal to be imprinted hereon.

                               QUESTAR GAS COMPANY


                                By:___________________________
                                   Name:
                                   Title:


ATTEST:


By:______________________
   Name:
   Title:


[SEAL]


Date:



TRUSTEE'S CERTIFICATE OF AUTHENTICATION:
This is one of the Securities of the
series designated herein, referred to in
the within-mentioned Indenture.

Wells Fargo Bank Northwest, National Association (f/k/a First Security Bank,
N.A.), as Trustee


By:__________________________________
           Authorized Signatory


                                       17


<Page>

                            ------------------------

                  The following abbreviations when used in the inscription on
this Note, shall be construed as though they were written out in full according
to applicable laws or regulations:


TEN COM - as tenants in common UNIF GIFT MIN ACT - ______ Custodian_________
TEN ENT - as tenants by the                        (Cust)           (Minor)
               entireties                          Under Uniform Gifts to Minor

JT TEN - as joint tenants with                     Act_________________________
               right of survivorship                           (State)
               and not as tenants
               in common

Additional abbreviations may also be used though not in the above list.

                            ------------------------

                  FOR VALUE RECEIVED, the undersigned hereby sells, assigns and
transfers unto


PLEASE INSERT SOCIAL SECURITY OR OTHER
IDENTIFYING NUMBER OF ASSIGNEE

--------------------------------------

--------------------------------------


(Please print or typewrite name and address including postal zip code of
assignee)

the within Note of Questar Gas Company and does hereby irrevocably constitute
and appoint

___________________________________________________________________Attorney to
transfer said Note on the books of said Company, with full power of substitution
in the premises.

Dated:

         NOTICE: The signature of the Holder to this assignment must correspond
with the name as it appears upon the face of the within Note in every
particular, without alteration or enlargement or any change whatsoever, and be
guaranteed by an acceptable bank or broker.


                                       18

<Page>

                            OPTION TO ELECT REPAYMENT

               The undersigned hereby irrevocably requests and instructs the
Company to repay the within Note (or portion hereof specified below) pursuant to
its terms at a price equal to 100% of the principal amount hereof, together with
interest thereon payable to the Optional Repayment Date, to the undersigned at

--------------------------------------------------------------------------------
         (Please Print or Typewrite Name and Address of the Undersigned)

               For this Note to be repaid, the trustee must receive this "Option
to Elect Repayment" form, duly completed, together with this Note not more than
60 nor less than 30 days prior to an Optional Repayment Date shown on the face
of this Note at its Corporate Trust Office, or at such other place or places
designated by the Company and notified by it to the Holder of this Note.

               If less than the entire principal amount of the within Note is to
be repaid, specify the portion thereof which the Holder elects to have repaid
________________ ______________________________; and specify the denomination or
denominations (which shall be authorized denominations) of the Notes to be
issued to the Holder for the portion of the within Note not being repaid (in the
absence of any specification, one such Note will be issued for the portion not
being repaid) _______________.


Date:___________________


                                    ------------------------------
                                    Note: The signature on this Option to Elect
                                    Repayment must correspond with the name as
                                    written in this Note in every particular
                                    without alteration or enlargement or any
                                    change whatsoever.


                                       19