RESTATED CERTIFICATE OF INCORPORATION
                            OREGON STEEL MILLS, INC.
             (originally incorporated June 21, 1972, under the name
                     GILMORE STEEL CORPORATION OF DELAWARE)


        FIRST:  The name of this Corporation is OREGON STEEL MILLS, INC.

        SECOND: This Corporation's registered office in the State of Delaware is
to be located at 1209 Orange Street,  in the City of  Wilmington,  County of New
Castle.  The name of its  registered  agent at such  address is the  Corporation
Trust Company.

        THIRD: The purpose of this Corporation is to engage in any lawful act or
activity for which corporations may be  organized under the General Corporation
Law of Delaware.

        FOURTH:

        (1) The  total  number  of  shares  of all  classes  of stock  which the
Corporation has the authority to issue is 31,000,000,  consisting of two classes
of shares of stock, to be designated Common Stock and Preferred Stock. The total
number of shares of Common Stock  authorized to be issued is 30,000,000  shares,
$0.01 par value per share,  and the total  number of shares of  Preferred  Stock
authorized to be issued is 1,000,000 shares, $0.01 par value per share.

        (2) The shares of Preferred Stock may be issued from time to time in one
or more series.  The Board of Directors of this  Corporation  is  authorized  to
provide for the issuance of the shares of the Preferred Stock in series,  and by
filing a certificate pursuant to the applicable law of the State of Delaware, to
establish  the number of shares to be  included  in such a series and to fix the
designation,  powers,  preferences  and rights of the shares of each such series
and any qualifications,  limitations or restrictions thereof,  including but not
limited to the dividend rights, dividend rate, conversion rights, voting rights,
rights and terms of  redemption  (including  sinking  fund  provisions)  and the
liquidation  preferences,  and the number of shares constituting any such series
and the  designation  thereof,  or any of  them;  and,  within  the  limits  and
restrictions  stated in any  resolution or resolutions of the Board of Directors
originally  fixing the  number of shares  constituting  any series of  Preferred
Stock,  to increase or decrease  (but not below the number of shares of any such
series then  outstanding)  the number of shares of any series  subsequent to the
issue of shares of such series. In case the number of shares of any series shall
be so decreased,  the shares  constituting such decrease shall resume the status
which they had prior to the  adoption of the  resolution  originally  fixing the
number of shares of such series.

1 - RESTATED CERTIFICATE OF INCORPORATION

<PAGE>

        FIFTH:

        (1) The number of directors  constituting  the entire Board of Directors
shall be not less than  three  (3) nor more than nine (9) as fixed  from time to
time by vote of a majority  of the entire  Board,  provided,  however,  that the
number  of  directors  shall not be  reduced  so as to  shorten  the term of any
director.

        (2) Commencing with the Annual Meeting of Stockholders held in 1988, the
Board of Directors  of this  Corporation  shall be divided  into three  Classes:
Class A, Class B and Class C. Each Class shall consist,  as nearly as reasonably
possible,  of  one-third  (1/3) of the  total  authorized  number  of  directors
constituting  the Board of  Directors.  Class A  directors  elected  at the 1988
Annual  Meeting of  Stockholders  shall  serve  initially  until the next annual
meeting  following their election (1989);  Class B directors elected at the 1988
Annual Meeting of  Stockholders  shall serve  initially  until the second annual
meeting  following their election (1990);  and Class C directors  elected at the
1988 Annual Meeting of Stockholders shall serve initially until the third annual
meeting following their election (1991). Any vacancies in the Board of Directors
for any reason, and any directorships  resulting from any increase in the number
of directors,  may be filled by the Board of Directors,  acting by a majority of
the directors then in office,  although less than a quorum, and any directors so
chosen  shall hold  office  until the next  election of the class for which such
directors shall have been chosen and until their successors shall be elected and
qualified. Subject to the foregoing, at each Annual Meeting of Stockholders, the
successors  to the class of  directors  whose term shall  then  expire  shall be
elected  to hold  office  for a term  expiring  at the third  succeeding  annual
meeting.

        (3) Notwithstanding any other provisions of this Restated Certificate of
Incorporation or the Bylaws of the Corporation, any director or the entire Board
of  Directors  may be  removed at any time,  but only for  cause,  as defined in
accordance with the General Corporation Law of the State of Delaware.

        SIXTH:  The Bylaws of this  Corporation  may be amended or repealed,  or
new bylaws may be adopted, by this Corporation's Board of Directors.

        SEVENTH:  Meetings of  stockholders  may be  held within  or without the
State of Delaware, as the Bylaws may provide.  The books of the  Corporation may
be kept (subject to  any provision  contained in the statutes) outside the State
of Delaware at such place or places as may be  designated  from  time to time by
the  Board of  Directors  or  in  the  Bylaws of the Corporation.  Elections for
directors need not be by ballot unless the Bylaws so require.

        EIGHTH:  A  director of the  Corporation shall  not be personally liable
to  this  Corporation or  its stockholders  for monetary  damages for  breach of
fiduciary duty as a director, except

2 - RESTATED CERTIFICATE OF INCORPORATION
<PAGE>


for  liability  (1) for any  breach of such  director's  duty of  loyalty to the
Corporation or its stockholders,  (2) for acts or omissions not in good faith or
which involve  intentional  misconduct or a knowing  violation of law, (3) under
Section 174 of the Delaware  General  Corporation Law or (4) for any transaction
from which the director derived any improper personal  benefit.  If the Delaware
General Corporation Law hereafter is amended,  changed or modified in any way to
further  eliminate or limit the liability of directors to the Corporation or its
stockholders  or  third  parties,  then the  directors  of the  Corporation,  in
addition to the  circumstances  in which directors are not personally  liable as
set forth in the preceding sentence,  shall also not be personally liable to the
Corporation or its  stockholders  or third parties for monetary  damages to such
further extent permitted by such amendment, change or modification.

        NINTH:   The  Corporation   shall  have  the  authority  to  enter  into
appropriate  agreements  with the  directors  and officers  (and with such other
employees and agents as the Board of Directors deems appropriate in its sole and
exclusive  discretion)  to both indemnity them and advance to them the funds for
litigation  expenses to the fullest extent permitted by the laws of the State of
Delaware as the same  presently  exist or may  hereafter be amended,  changed or
modified.

        TENTH:  The  Corporation  reserves  the  right to amend and  repeal  any
provision contained in this Restated  Certificate of Incorporation,  and to take
other  corporate  action  to  the  extent  and in the  manner  now or  hereafter
permitted or prescribed by the laws of the State of Delaware.  All rights herein
conferred are granted subject to this reservation.

        ELEVENTH:  The Corporation is to have perpetual existence.

        IN WITNESS WHEREOF,  this Restated  Certificate of  Incorporation  which
restates and integrates and also further amends the Corporation's Certificate of
Incorporation  as  heretofore  amended,  having been adopted and approved by the
stockholders  and directors of the  Corporation in accordance  with Sections 242
and 245 of the  Delaware  General  Corporation  Law  has  been  executed  by the
undersigned officers of the Corporation as of the 27th day of September, 1990.



                                       /s/ Thomas B. Boklund
                                       -----------------------------------------
                                       President

ATTESTED BY:


/s/ Milo Long
---------------------------
Secretary

3 - RESTATED CERTIFICATE OF INCORPORATION

<PAGE>

                            CERTIFICATE OF AMENDMENT
                    OF RESTATED CERTIFICATE OF INCORPORATION
                           OF OREGON STEEL MILLS, INC.

        The undersigned, Thomas B. Boklund and L. Ray Adams, hereby certify that
they are, and at all times herein  mentioned  have been  respectively,  the duly
elected and acting Chief Executive  Officer and Secretary of Oregon Steel Mills,
Inc., a Delaware corporation, and further certify that:

        1.  Paragraph  (1)  of  Article  FIFTH  of the  Restated  Certificate of
Incorporation of Oregon Steel Mills, Inc. is  hereby deleted in its entirety and
the following is hereby inserted in lieu thereof:

        (1)  FIFTH:  The  number of  directors  constituting  the  entire  Board
        OF Directors shall be not less than three (3) nor more than  twelve (12)
        as fixed  from time to time  by vote of a majority of the  entire Board,
        provided,  however, that the number of directors shall not be reduced so
        as to shorten the term of any director.

        2.  The  foregoing  amendment  has  been  duly  approved by the Board of
Directors.

        3.  Pursuant  to a  resolution  of the Board of  Directors,  the  Annual
Meeting  of the  stockholders  was duly  called  and held on April  21,  1992 in
accordance  with  Section  222 of the  General  Corporation  Law of the State of
Delaware, at which meeting the necessary number of shares as required by statute
were voted in favor of the amendment set forth at 1 above.

        4. The  amendment  set forth in 1 above was duly  adopted in  accordance
with  Section  242 of the  General  Corporation  Law of the State of Delaware on
April 21, 1992.

                                   /s/ Thomas B. Boklund
                                   ------------------------------------------
                                   Thomas B. Boklund, Chief Executive Officer

                                   /s/ L. Ray Adams
                                   ------------------------------------------
                                   L. Ray Adams, Secretary

1 - CERTIFICATE OF AMENDMENT OF RESTATED CERTIFICATE OF INCORPORATION

<PAGE>

        The undersigned  certifies under penalty of perjury that he has read the
foregoing  Certificate of Amendment to the Restated Certificate of Incorporation
and knows the content thereof, and that the statements therein are true.

        Executed at Portland, Oregon, this 1 day of June, 1992.

                                   /s/ L. Ray Adams
                                   ------------------------------------------
                                   L. Ray Adams, Secretary

2 - CERTIFICATE OF AMENDMENT OF RESTATED CERTIFICATE OF INCORPORATION

<PAGE>

                      CERTIFICATE OF OWNERSHIP AND MERGER
                                       OF
                             NAPA PIPE CORPORATION
                             a Delaware corporation
                                      INTO
                            OREGON STEEL MILLS, INC.
                             a Delaware corporation

  (Under Section 253 of the General Corporation Law of the State of Delaware)


OREGON STEEL MILLS, INC. certifies that:

     1.   The  name  and  state  of  incorporation  of each  of the  constituent
          corporations are:

          a.  NAPA PIPE CORPORATION, a Delaware corporation (the "Subsidiary
              Corporation"); and

          b.  OREGON STEEL MILLS, INC., a Delaware corporation (the "Parent
              Corporation").

     2.   The  Parent  Corporation  owns  all of the  outstanding  stock  of the
          Subsidiary  Corporation and shall be the surviving  corporation in the
          merger.

     3.   A resolution authorizing the merger of the Subsidiary Corporation with
          and into the Parent  Corporation  was approved and adopted on February
          1,  1996 by the  Board  of  Directors  of the  Parent  Corporation  in
          accordance  with Section 253(a) of the General  Corporation Law of the
          State of Delaware. A certified copy of the resolution  authorizing the
          merger is attached hereto.

     4.   The  outstanding  shares of the  Subsidiary  Corporation  shall not be
          converted  into  shares  of  the  Parent  Corporation,  but  shall  be
          cancelled,  and the authorized capital stock of the Parent Corporation
          shall not be  changed,  but shall be and remain the same as before the
          merger.

     5.   The state of  incorporation  of the  Parent  Corporation  shall be and
          remain the State of Delaware.

     6.   The officers and directors of the Parent Corporation shall be the same
          officers and  directors in office  immediately  prior to the effective
          date of the merger.

     7.   All  provisions of the existing  Certificate of  Incorporation  of the
          Parent  Corporation,  on file with the  Delaware  Secretary  of State,
          shall  constitute  the  Certificate  of  Incorporation  of the  Parent
          Corporation.

     8.   All provisions of the existing Bylaws of the Parent  Corporation shall
          constitute the Bylaws of the Parent Corporation.

1 - CERTIFICATE OF OWNERSHIP AND MERGER

<PAGE>

     9.   The Subsidiary  Corporation and the Parent  Corporation shall take, or
          cause to be taken,  all action,  or do or cause to be done, all things
          necessary,  proper or advisable  under the General  Corporation Law of
          the State of Delaware, to consummate and make effective the merger.

     10.  The  merger  shall be  effective  the date and time of  filing of this
          Certificate of Ownership and Merger.

          IN  WITNESS   WHEREOF,  OREGON  STEEL  MILLS,  INC.  has  caused  this
Certificate  of  Ownership  and  Merger to  be signed  and  acknowledged  by the
undersigned officer of the  Corporation on this 1st day of February,  1996. The
undersigned  certifies under penalty  of perjury that he  has read the foregoing
Certificate of Ownership and Merger and knows the content  thereof, and that all
statements  therein are true.

                                        OREGON STEEL MILLS, INC.



                                        /s/ Thomas B. Boklund
                                        ----------------------------------------
                                        By:     Thomas B. Boklund
                                        Title:  Chief Executive Officer

2 - CERTIFICATE OF OWNERSHIP AND MERGER

<PAGE>


                      CERTIFICATE OF OWNERSHIP AND MERGER
                                       OF
                   OREGON STEEL MILLS-FONTANA DIVISION, INC.
                             a Delaware corporation
                                      INTO
                            OREGON STEEL MILLS, INC.
                             a Delaware corporation

  (Under Section 253 of the General Corporation Law of the State of Delaware)


OREGON STEEL MILLS, INC. certifies that:

     1.  The  name  and  state  of  incorporation  of  each  of the  constituent
         corporations are:

          a.   OREGON STEEL MILLS-FONTANA DIVISION, INC., a Delaware corporation
               (the "Subsidiary Corporation"); and

          b.   OREGON STEEL MILLS,  INC.,  a Delaware  corporation  (the "Parent
               Corporation").

     2.   The  Parent  Corporation  owns  all of the  outstanding  stock  of the
          Subsidiary  Corporation and shall be the surviving  corporation in the
          merger.

     3.   A resolution authorizing the merger of the Subsidiary Corporation with
          and into the Parent  Corporation  was approved and adopted on February
          1,  1996 by the  Board  of  Directors  of the  Parent  Corporation  in
          accordance  with Section 253(a) of the General  Corporation Law of the
          State of Delaware. A certified copy of the resolution  authorizing the
          merger is attached hereto.

     4.   The  outstanding  shares of the  Subsidiary  Corporation  shall not be
          converted  into  shares  of  the  Parent  Corporation,  but  shall  be
          cancelled,  and the authorized capital stock of the Parent Corporation
          shall not be  changed,  but shall be and remain the same as before the
          merger.

     5.   The state of  incorporation  of the  Parent  Corporation  shall be and
          remain the State of Delaware.

     6.   The officers and directors of the Parent Corporation shall be the same
          officers and  directors in office  immediately  prior to the effective
          date of the merger.

     7.   All  provisions of the existing  Certificate of  Incorporation  of the
          Parent  Corporation,  on file with the  Delaware  Secretary  of State,
          shall  constitute  the  Certificate  of  Incorporation  of the  Parent
          Corporation.

1 - CERTIFICATE OF OWNERSHIP AND MERGER

<PAGE>

     8.   All provisions of the existing Bylaws of the Parent  Corporation shall
          constitute the Bylaws of the Parent Corporation.

     9.   The Subsidiary  Corporation and the Parent  Corporation shall take, or
          cause to be taken,  all action,  or do or cause to be done, all things
          necessary,  proper or advisable  under the General  Corporation Law of
          the State of Delaware, to consummate and make effective the merger.

     10.  The  merger  shall be  effective  the date and time of  filing of this
          Certificate of Ownership and Merger.

        IN WITNESS WHEREOF, OREGON STEEL MILLS, INC. has caused this Certificate
of Ownership and Merger to be signed and acknowledged by the undersigned officer
of the Corporation on this 1st day of February, 1996. The undersigned certifies
under penalty of perjury that he has read the foregoing Certificate of Ownership
and Merger and knows the content  thereof,  and that all statements  therein are
true.

                                        OREGON STEEL MILLS, INC.



                                        /s/ Thomas B. Boklund
                                        ----------------------------------------
                                        By:  Thomas B. Boklund
                                        Title:  Chief Executive Officer

2 - CERTIFICATE OF OWNERSHIP AND MERGER

<PAGE>

                         Certificate of Designations of
                        Participating Preferred Stock of
                            Oregon Steel Mills, Inc.

                         Pursuant to Section 151 of the
                        Delaware General Corporation Law

      I, L. Ray Adams, Vice President of Oregon Steel Mills, Inc., a corporation
organized  and  existing  under  the  Delaware  General   Corporation  Law  (the
"Corporation"), in accordance with the provisions of Section 151 of such law, DO
HEREBY  CERTIFY:  that  pursuant to the  authority  conferred  upon the Board of
Directors by the Restated  Certificate of Incorporation of the Corporation,  the
Board of Directors on December 23, 1999 adopted the following  resolution  which
creates a series of Six Hundred  Thousand  (600,000)  shares of preferred  stock
designated as Participating Preferred Stock, as follows:

     RESOLVED,   that  pursuant  to  Section  151(g)  of  the  Delaware  General
Corporation  Law and the  authority  vested  in the  Board of  Directors  of the
Corporation in accordance  with the provisions of FOURTH ARTICLE of the Restated
Certificate of Incorporation of the Corporation,  a series of Preferred Stock of
the Corporation be, and is, created, and the powers,  designations,  preferences
and relative,  participating,  optional or other special rights of the shares of
such series, and the qualifications,  limitations or restrictions  thereof,  be,
and are, as follows[ko1]:

Section 1. Designation and Amount.

     The shares of such series shall be designated as  "Participating  Preferred
Stock"  (the   "Participating   Preferred  Stock")  and  the  number  of  shares
constituting  such series shall be Six Hundred  Thousand  (600,000).

Section 2. Dividends  and  Distributions.

     (A) Subject to the  provisions for adjustment  hereinafter  set forth,  the
holders of shares of Participating Preferred Stock shall be entitled to receive,
when,  as and if  declared  by the  Board  of  Directors  out of  funds  legally
available for the purpose, (i) cash dividends in an amount per share (rounded to
the nearest  cent) equal to 1,000 times the  aggregate  per share  amount of all
cash dividends  declared or paid on the Common Stock, $0.01 par value per share,
of the Corporation  (the "Common  Stock") and (ii) a preferential  cash dividend
(the "Preferential  Dividends"),  if any, in preference to the holders of Common
Stock, on the last day of February,  May, August and November of each year (each
a "Quarterly Dividend Payment Date"), commencing on the first Quarterly Dividend
Payment  Date  after the first  issuance  of a share or  fraction  of a share of
Participating  Preferred Stock,  payable in an amount (except in the case of the
first  Quarterly  Dividend  Payment  if  the  date  of  the  first  issuance  of
Participating  Preferred Stock is a date other than a Quarterly Dividend Payment
date,  in which case such  payment  shall be a prorated  amount of such  amount)
equal to $.01 per  share of  Participating  Preferred  Stock  less the per share
amount of all cash  dividends  declared  on the  Participating  Preferred  Stock
pursuant  to  clause  (i) of  this  sentence  since  the  immediately  preceding
Quarterly Dividend Payment Date or, with respect to the first Quarterly Dividend
Payment  Date,  since the first  issuance of any share or fraction of a share of
Participating  Preferred Stock. In the event the Corporation  shall, at any time
after  the  issuance  of any  share  or  fraction  of a share  of

                                       1
<PAGE>

Participating  Preferred  Stock,  make any  distribution on the shares of Common
Stock of the Corporation,  whether by way of a dividend or a reclassification of
stock,  a  recapitalization,   reorganization  or  partial  liquidation  of  the
Corporation or otherwise,  which is payable in cash or any debt  security,  debt
instrument,  real or personal  property or any other  property  (other than cash
dividends  subject to the  immediately  preceding  sentence,  a distribution  of
shares  of  Common  Stock  or  other  capital  stock  of  the  Corporation  or a
distribution of rights or warrants to acquire any such share, including any debt
security  convertible  into or exchangeable  for any such share, at a price less
than the Fair Market Value (as hereinafter defined) of such share), then, and in
each  such  event,  the  Corporation  shall  simultaneously  pay  on  each  then
outstanding  share  of  Participating  Preferred  Stock  of  the  Corporation  a
distribution,  in like kind, of 1,000 times such distribution paid on a share of
Common Stock (subject to the provisions for adjustment  hereinafter  set forth).
The dividends and  distributions on the  Participating  Preferred Stock to which
holders  thereof are  entitled  pursuant to clause (i) of the first  sentence of
this  paragraph  and  pursuant  to the second  sentence  of this  paragraph  are
hereinafter  referred  to as  "Dividends"  and the  multiple  of such  cash  and
non-cash  dividends on the Common Stock  applicable to the  determination of the
Dividends,  which shall be 1,000  initially  but shall be adjusted  from time to
time as  hereinafter  provided,  is  hereinafter  referred  to as the  "Dividend
Multiple." In the event the Corporation shall at any time after January 12, 2000
(i) declare or pay any dividend or make any distribution on Common Stock payable
in shares of Common Stock,  (ii) effect a subdivision or split or a combination,
consolidation or reverse split of the outstanding  shares of Common Stock into a
greater or lesser number of shares of Common Stock, or (iii) issue any shares of
its capital stock in a reclassification  of the Common Stock (including any such
reclassification  in  connection  with a  consolidation  or  merger in which the
Corporation is the continuing or surviving corporation),  then in each such case
the Dividend Multiple  thereafter  applicable to the determination of the amount
of Dividends which holders of shares of  Participating  Preferred Stock shall be
entitled to receive shall be the Dividend Multiple applicable  immediately prior
to such event  multiplied  by a fraction the numerator of which is the number of
shares  of  Common  Stock  outstanding  immediately  after  such  event  and the
denominator  of  which is the  number  of  shares  of  Common  Stock  that  were
outstanding  immediately  prior to such event.

     (B) The  Corporation  shall  declare  each  Dividend  at the  same  time it
declares any cash or non-cash  dividend or  distribution  on the Common Stock in
respect of which a Dividend is required to be paid. No cash or non-cash dividend
or  distribution  on the Common Stock in respect of which a Dividend is required
to be paid shall be paid or set aside for payment on the Common  Stock  unless a
Dividend in respect of such dividend or  distribution  on the Common Stock shall
be simultaneously paid, or set aside for payment, on the Participating Preferred
Stock;  provided that, in the event that no dividend or distribution is declared
on the Common Stock during any period  between any  Quarterly  Dividend  Payment
Date and the next Quarterly  Dividend Payment Date, the  Preferential  Dividends
shall  nevertheless be payable on such next Quarterly Dividend Payment Date.

     (C) Preferential  Dividends shall begin to accrue on outstanding  shares of
Participating  Preferred  Stock from the  Quarterly  Dividend  Payment Date next
preceding the date of issuance of any shares of  Participating  Preferred Stock,
unless  the date of issue of such  shares  is prior to the  record  date for the
first  Quarterly  Dividend  Payment Date, in which case dividends on such shares
shall begin to accrue from the date of issue of such shares,  or unless the date
of issue is a Quarterly Dividend Payment Date or is a date after the record date
for determination of holders of shares of Participating Preferred Stock entitled
to receive a Preferential  Dividend and before such Quarterly  Dividend  Payment
Date,  in either of which  events  such  dividends  shall begin to

                                      2

<PAGE>

accrue and be cumulative from such Quarterly  Dividend Payment Date. Accrued but
unpaid  Preferential  Dividends  shall  cumulate  but  shall  not bear  interest
Preferential Dividends paid on the shares of Participating Preferred Stock in an
amount  less than the total  amount of such  dividends  at the time  accrued and
payable on such shares shall be  allocated  pro rata on a  share-by-share  basis
among all such shares at the time outstanding.  The Board of Directors may fix a
record  date for the  determination  of holders of the  Participating  Preferred
Stock  entitled  to  receive  payment  of a dividend  or  distribution  declared
thereon, which record date shall be no more than 30 days prior to the date fixed
for the  payment  thereof.

Section 3. Voting  Rights.

     The  holders  of shares of  Participating  Preferred  Stock  shall have the
following   voting  rights:

     (A) Subject to the provisions for adjustment  hereinafter  set forth,  each
share of Participating Preferred Stock shall entitle the holder thereof to 1,000
votes on all matters submitted to a vote of the holders of the Common Stock. The
number of votes which a holder of  Participating  Preferred Stock is entitled to
cast, as the same may be adjusted from time to time as hereinafter  provided, is
hereinafter  referred to as the "Vote  Multiple."  In the event the  Corporation
shall at any time after  January 12,  2000,  (i) declare or pay any  dividend on
Common Stock  payable in shares of Common Stock,  (ii) effect a  subdivision  or
split or a combination, consolidation or reverse split of the outstanding shares
of Common Stock into a greater or lesser  number of shares of Common  Stock,  or
(iii) issue any shares of its capital stock in a reclassification  of the Common
Stock (including any such reclassification in connection with a consolidation or
merger in which the  Corporation  is the  continuing or surviving  corporation),
then  in  each  such  case  the  Vote  Multiple  thereafter  applicable  to  the
determination  of the  number of votes per share to which  holders  of shares of
Participating  Preferred  Stock shall be entitled  after such event shall be the
Vote  Multiple  immediately  prior to such event  multiplied  by a fraction  the
numerator  of  which  is the  number  of  shares  of  Common  Stock  outstanding
immediately  after  such  event and the  denominator  of which is the  number of
shares of Common Stock that were  outstanding  immediately  prior to such event.

     (B) Except as otherwise  provided  herein,  in the  Corporation's  Restated
Certificate  of  Incorporation  or Bylaws,  or by law,  the holders of shares of
Participating  Preferred  Stock and the holders of shares of Common  Stock shall
vote together as one class on all matters submitted to a vote of stockholders of
the Corporation.

     (C)  In  the  event  that  the  Preferential   Dividends   accrued  on  the
Participating  Preferred Stock for four or more  consecutive  quarterly  periods
shall not have been  declared and paid or set apart for payment,  the holders of
record of the Participating Preferred Stock, voting together with the holders of
record of any other series of  preferred  stock of the  Corporation  which shall
then  have  the  right,   expressly  granted  by  the  Restated  Certificate  of
Incorporation  of the  Corporation  or in any  resolution or  resolutions of the
Board of Directors of the Corporation  providing for the issue of such shares of
preferred  stock,  to elect  directors  upon such a default  in the  payment  of
dividends  by the  Corporation  shall  have the  right,  at the next  meeting of
stockholders  called for the election of directors,  voting together as a class,
to elect two members to the Board of Directors, which directors shall be elected
to fill any then  existing  vacancies on the Board of  Directors,  or if no such
vacancies  exist or if the number of  vacancies  is  insufficient  to allow such
stockholders  to  elect  two  directors,  then  the  directors  elected  by such
stockholders  shall be in addition to the number  provided  for  pursuant to the
Corporation's Bylaws prior to such event, to

                                       3

<PAGE>

serve until the next annual  meeting and until their  successors are elected and
qualified or their  earlier  resignation,  removal or  incapacity  or until such
earlier  time  as  all  accrued  and  unpaid  Preferential  Dividends  upon  the
outstanding shares of Participating Preferred Stock shall have been paid (or set
aside for  payment) in full.  The holders of shares of  Participating  Preferred
Stock  shall  continue to have the right to elect  directors  as provided by the
immediately  preceding  sentence  until  all  accrued  and  unpaid  Preferential
Dividends upon the  outstanding  shares of  Participating  Preferred Stock shall
have been paid (or set aside for payment) in full. Such directors may be removed
and replaced by such  stockholders,  and vacancies in such  directorships may be
filled only by such  stockholders (or by the remaining  director elected by such
stockholders,  if there be one) in the manner  permitted by law.  Subject to the
foregoing,  any  directors  elected  pursuant  to this  paragraph  3(C) shall be
elected  annually and shall not constitute  members of any Class of directors as
contemplated  by Fifth  Article of the  Corporation's  Restated  Certificate  of
Incorporation.

     (D) Except as otherwise required by the Corporation's  Restated Certificate
of  Incorporation  or Bylaws  or set  forth  herein,  holders  of  Participating
Preferred  Stock shall have no other  special  voting  rights and their  consent
shall not be  required  (except to the  extent  they are  entitled  to vote with
holders of Common  Stock as set forth  herein)  for the taking of any  corporate
action.

Section 4. Certain Restrictions.

     (A) Whenever  Preferential  Dividends  or  Dividends  are in arrears or the
Corporation  shall be in default of payment  thereof,  thereafter  and until all
accrued  and  unpaid  Preferential  Dividends  and  Dividends,  whether  or  not
declared, on shares of Participating Preferred Stock outstanding shall have been
paid or set  irrevocably  aside for payment in full,  and in addition to any and
all other rights which any holder of shares of Participating Preferred Stock may
have in such  circumstances,  the  Corporation  shall  not

  (i)  declare  or pay
dividends  on,  make any  other  distributions  on, or  redeem  or  purchase  or
otherwise acquire for consideration,  any shares of stock ranking junior (either
as to  dividends  or  upon  liquidation,  dissolution  or  winding  up)  to  the
Participating  Preferred  Stock;

  (ii)  declare or pay  dividends on or make any
other  distributions  on any shares of stock  ranking on a parity  (either as to
dividends or upon  liquidation,  dissolution or winding up) as to dividends with
the  Participating  Preferred  Stock,  unless  dividends are paid ratably on the
Participating  Preferred  Stock and all such parity stock on which dividends are
payable or in arrears in proportion to the total amounts to which the holders of
all such shares are then entitled if the full dividends  accrued thereon were to
be paid;

  (iii) except as permitted by  subparagraph (iv) of this Section 4(A),
redeem or purchase or otherwise  acquire for  consideration  shares of any stock
ranking on a parity (either as to dividends or upon liquidation,  dissolution or
winding  up)  with  the  Participating   Preferred  Stock,   provided  that  the
Corporation may at any time redeem,  purchase or otherwise acquire shares of any
such parity stock in exchange for shares of any stock of the Corporation ranking
junior (both as to dividends and upon liquidation, dissolution or winding up) to
the  Participating  Preferred  Stock; or

 (iv) purchase or otherwise  acquire for
consideration  any shares of  Participating  Preferred  Stock,  or any shares of
stock ranking on a parity with the  Participating  Preferred Stock

                                       4

<PAGE>

(either as to dividends or upon liquidation,  dissolution or winding up), except
in accordance with a purchase offer made to all holders of such shares upon such
terms as the Board of Directors,  after  consideration of the respective  annual
dividend  rates and other  relative  rights and  preferences  of the  respective
series and  classes,  shall  determine  in good  faith  will  result in fair and
equitable treatment among the respective series or classes.

     (B) The  Corporation  shall  not  permit  any  Subsidiary  (as  hereinafter
defined) of the Corporation to purchase or otherwise  acquire for  consideration
any shares of stock of the  Corporation  unless  the  Corporation  could,  under
paragraph  (A) of this Section 4,  purchase or otherwise  acquire such shares at
such time and in such manner.  A "Subsidiary" of the Corporation  shall mean any
corporation  or other entity of which  securities or other  ownership  interests
having  ordinary  voting  power  sufficient  to elect a majority of the Board of
Directors  of such  corporation  or other  entity  or other  persons  performing
similar  functions  are  beneficially  owned,  directly  or  indirectly,  by the
Corporation or by any  corporation or other entity that is otherwise  controlled
by  the  Corporation.

     (C) The Corporation  shall not issue any shares of Participating  Preferred
Stock except upon  exercise of Rights  issued  pursuant to that  certain  Rights
Agreement  dated as of December 23, 1999 between the Corporation and ChaseMellon
Shareholder Services,  LLC, as Rights Agent, a copy of which is on file with the
Secretary of the Corporation at its principal executive office and shall be made
available  to  stockholders  of  record  without  charge  upon  written  request
addressed to the  Secretary of the  Corporation.  Notwithstanding  the foregoing
sentence,   nothing   contained  in  the  provisions  of  this   Certificate  of
Designations  shall  prohibit or restrict the  Corporation  from issuing for any
purpose any series of  Preferred  Stock with rights and  privileges  similar to,
different from, or greater than,  those of the  Participating  Preferred  Stock.

Section 5.  Reacquired  Shares.

     Any shares of Participating Preferred Stock purchased or otherwise acquired
by the  Corporation  in any  manner  whatsoever  shall be retired  and  canceled
promptly after the acquisition  thereof.  All such shares upon their  retirement
and cancellation shall become authorized but unissued shares of Preferred Stock,
without  designation as to series,  and such shares may be reissued as part of a
new series of Preferred  Stock to be created by resolution or resolutions of the
Board of Directors.

 Section 6. Liquidation,  Dissolution or Winding Up.

     Upon any voluntary or involuntary liquidation, dissolution or winding up of
the Corporation,  no distribution  shall be made (i) to the holders of shares of
stock ranking junior (either as to dividends or upon liquidation, dissolution or
winding up) to the Participating Preferred Stock unless the holders of shares of
Participating  Preferred  Stock shall have  received,  subject to  adjustment as
hereinafter provided, (A) $1.00 per one one-thousandth (1/1,000) of a share plus
an amount  equal to accrued  and unpaid  dividends  and  distributions  thereon,
whether or not declared, to the date of such payment or, (B) if greater than the
amount  specified in clause  (i)(A) of this  sentence,  an amount equal to 1,000
times the  aggregate  amount to be  distributed  per share to  holders of Common
Stock,  as the same may be  adjusted  as  hereinafter  provided  and (ii) to the
holders of stock ranking on a parity with the Participating Preferred Stock upon
liquidation,   dissolution  or  winding  up,  unless  simultaneously   therewith
distributions  are made  ratably on the  Participating  Preferred  Stock and all
other shares of such parity stock in  proportion  to the total  amounts to which
the holders of shares of Participating Preferred Stock are entitled

                                       5

<PAGE>

under  clause  (i)(A) of this  sentence  and to which the holders of such parity
shares are entitled, in each case upon such liquidation,  dissolution or winding
up. The amount to which holders of Participating Preferred Stock may be entitled
upon  liquidation,  dissolution or winding up of the  Corporation is hereinafter
referred to as the  "Participating  Liquidation  Amount" and the multiple of the
amount  to be  distributed  to  holders  of  shares  of  Common  Stock  upon the
liquidation, dissolution or winding up of the Corporation applicable pursuant to
clause (i)(B) of the foregoing  sentence,  as said multiple may be adjusted from
time  to  time  as  hereinafter  provided,  is  hereinafter  referred  to as the
"Liquidation   Multiple."   Following  payment  in  full  of  the  Participating
Liquidation Amount, the liquidation preferences of all other series of preferred
stock, if any, that rank on a parity with the Participating Preferred Stock, and
any amounts  payable upon  liquidation,  dissolution or winding up to holders of
Common Stock, holders of shares of Participating  Preferred Stock and holders of
shares of Common Stock shall receive their  ratable and  proportionate  share of
the remaining assets to be distributed in the ratio of the Liquidation  Multiple
to 1 for the Participating  Preferred Stock and Common Stock,  respectively.  In
the event the  Corporation  shall at any time after January 12, 2000 (i) declare
or pay any  dividend on Common  Stock  payable in shares of Common  Stock,  (ii)
effect a subdivision or split or a combination,  consolidation  or reverse split
of the  outstanding  shares of Common  Stock into a greater or lesser  number of
shares of Common  Stock,  or (iii)  issue any shares of its  capital  stock in a
reclassification  of the Common Stock  (including any such  reclassification  in
connection with a consolidation or merger in which the Corporation is continuing
or surviving  corporation),  then, in each such case, the  Liquidation  Multiple
thereafter  applicable to the  determination  of the  Participating  Liquidation
Amount to which holders of Participating Preferred Stock shall be entitled after
such event shall be the Liquidation  Multiple  applicable  immediately  prior to
such event  multiplied  by a fraction  the  numerator  of which is the number of
shares  of  Common  Stock  outstanding  immediately  after  such  event  and the
denominator  of  which is the  number  of  shares  of  Common  Stock  that  were
outstanding immediately prior to such event.

Section 7. Certain Reclassification and Other Events.

     (A) In the event that holders of shares of Common Stock of the  Corporation
receive  after  January 12, 2000 in respect of their  shares of Common Stock any
share of capital stock of the Corporation  (other than any share of Common Stock
of the  Corporation),  whether  by way  of  reclassification,  recapitalization,
reorganization,  dividend or other  distribution or otherwise (a "Transaction"),
then, and in each such event, the dividend rights, voting rights and rights upon
the  liquidation,  dissolution or winding up of the Corporation of the shares of
Participating  Preferred  Stock  shall be  adjusted so that after such event the
holders of Participating  Preferred Stock shall be entitled,  in respect of each
share of  Participating  Preferred  Stock  held,  in  addition to such rights in
respect  thereof to which such  holder was  entitled  immediately  prior to such
adjustment,  to (i) such additional  dividends as equal the Dividend Multiple in
effect  immediately  prior  to such  Transaction  multiplied  by the  additional
dividends  which the  holder of a share of Common  Stock  shall be  entitled  to
receive by virtue of the receipt in the Transaction of such capital stock,  (ii)
such additional  voting rights as equal the Vote Multiple in effect  immediately
prior to such Transaction  multiplied by the additional  voting rights which the
holder of a share of Common  Stock shall be entitled to receive by virtue of the
receipt in the  Transaction  of such  capital  stock and (iii)  such  additional
distributions upon liquidation,  dissolution or winding up of the Corporation as
equal the Liquidation  Multiple in effect  immediately prior to such Transaction
multiplied by the additional  amount which the holder of a share of Common Stock
shall be entitled to receive upon liquidation,  dissolution or winding up of the
Corporation  by virtue of the

                                       6
<PAGE>

receipt in the  Transaction  of such capital  stock,  as the case may be, all as
provided by the terms of such  capital  stock.

     (B) In the event that holders of shares of Common Stock of the  Corporation
receive  after  January 12, 2000 in respect of their  shares of Common Stock any
right or warrant to purchase  Common Stock  (including as such a right,  for all
purposes of this paragraph,  any security  convertible  into or exchangeable for
Common Stock) at a purchase price per share less than the Fair Market Value of a
share of Common Stock on the date of issuance of such right or warrant, then and
in each such event the  dividend  rights,  voting  rights  and  rights  upon the
liquidation,  dissolution  or  winding  up of the  Corporation  of the shares of
Participating  Preferred  Stock  shall each be adjusted so that after such event
the Dividend Multiple, the Vote Multiple and the Liquidation Multiple shall each
be the product of the Dividend  Multiple,  the Vote Multiple and the Liquidation
Multiple,  as the  case  may be,  in  effect  immediately  prior  to such  event
multiplied by a fraction the numerator of which shall be the number of shares of
Common Stock outstanding  immediately before such issuance of rights or warrants
plus the maximum  number of shares of Common Stock which could be acquired  upon
exercise  in full of all such rights or warrants  and the  denominator  of which
shall be the number of shares of Common  Stock  outstanding  immediately  before
such  issuance of rights or warrants  plus the number of shares of Common  Stock
which could be  purchased,  at the Fair Market  Value of the Common Stock at the
time of such  issuance,  by the maximum  aggregate  consideration  payable  upon
exercise in full of all such rights or  warrants.

     (C) In the event that holders of shares of Common Stock of the  Corporation
receive  after  January 12, 2000 in respect of their  shares of Common Stock any
right or warrant to purchase capital stock of the Corporation (other than shares
of Common Stock), including as such a right, for all purposes of this paragraph,
any  security  convertible  into  or  exchangeable  for  capital  stock  of  the
Corporation  (other than Common Stock),  at a purchase price per share less than
the Fair Market Value of such shares of capital stock on the date of issuance of
such right or warrant,  then and in each such event the dividend rights,  voting
rights and rights upon liquidation, dissolution or winding up of the Corporation
of the shares of  Participating  Preferred  Stock shall each be adjusted so that
after such event each holder of a share of  Participating  Preferred Stock shall
be entitled, in respect of each share of Participating  Preferred Stock held, in
addition  to such rights in respect  thereof to which such  holder was  entitled
immediately  prior to such event,  to receive (i) such  additional  dividends as
equal  the  Dividend  Multiple  in  effect   immediately  prior  to  such  event
multiplied, first, by the additional dividends to which the holder of a share of
Common Stock shall be entitled  upon exercise of such right or warrant by virtue
of the capital stock which could be acquired  upon such exercise and  multiplied
again by the Discount Fraction (as hereinafter defined) and (ii) such additional
voting  rights as equal the Vote  Multiple in effect  immediately  prior to such
event multiplied,  first, by the additional voting rights to which the holder of
a share of Common Stock shall be entitled upon exercise of such right or warrant
by virtue of the capital  stock which could be acquired  upon such  exercise and
multiplied   again  by  the  Discount   Fraction   and  (iii)  such   additional
distributions upon liquidation,  dissolution or winding up of the Corporation as
equal  the  Liquidation  Multiple  in  effect  immediately  prior to such  event
multiplied,  first,  by the  additional  amount  which the  holder of a share of
Common  Stock shall be  entitled to receive  upon  liquidation,  dissolution  or
winding up of the  Corporation  upon exercise of such right or warrant by virtue
of the capital stock which could be acquired  upon such exercise and  multiplied
again by the Discount  Fraction.  For purposes of this paragraph,  the "Discount
Fraction"  shall be a fraction the  numerator  of which shall be the  difference
between the Fair Market Value of a share of the capital stock subject to a

                                       7

<PAGE>

right or  warrant  distributed  to  holders  of shares  of  Common  Stock of the
Corporation as contemplated by this paragraph immediately after the distribution
thereof  and the  purchase  price  per  share for such  share of  capital  stock
pursuant to such right or warrant and the denominator of which shall be the Fair
Market Value of a share of such capital stock immediately after the distribution
of such right or warrant.

     (D) For  purposes of this  Certificate  of  Designations,  the "Fair Market
Value" of a share of  capital  stock of the  Corporation  (including  a share of
Common Stock) on any date shall be deemed to be the average of the daily closing
price per share  thereof over the 30  consecutive  Trading Days (as such term is
hereinafter defined) immediately prior to such date; provided, however, that, in
the event that such Fair  Market  Value of any such  share of  capital  stock is
determined  during a period  which  includes  any date that is within 30 Trading
Days after (i) the  ex-dividend  date for a dividend  or  distribution  on stock
payable in shares of such stock or  securities  convertible  into shares of such
stock,  or (ii)  the  effective  date of any  subdivision,  split,  combination,
consolidation,  reverse stock split or reclassification of such stock, then, and
in each such case, the Fair Market Value shall be appropriately  adjusted by the
Board of  Directors  of the  Corporation  to take into  account  ex-dividend  or
post-effective  date  trading.  The closing  price for any day shall be the last
sale price,  regular way, or, in case, no such sale takes place on such day, the
average of the closing bid and asked  prices,  regular way (in either  case,  as
reported  in  the  applicable  transaction  reporting  system  with  respect  to
securities listed or admitted to trading on the New York Stock Exchange), or, if
the shares are not listed or admitted to trading on the New York Stock Exchange,
as reported  in the  applicable  transaction  reporting  system with  respect to
securities  listed on the principal  national  securities  exchange on which the
shares are  listed or  admitted  to trading  or, if the shares are not listed or
admitted to trading on any national securities  exchange,  the last quoted price
or, if not so quoted,  the  average of the high bid and low asked  prices in the
over-the-counter  market, as reported by the National  Association of Securities
Dealers, Inc. Automated Quotation System ("NASDAQ") or such other system then in
use, or if on any such date the shares are not quoted by any such  organization,
the average of the closing bid and asked prices as  furnished by a  professional
market maker making a market in the shares selected by the Board of Directors of
the Corporation.  The term "Trading Day" shall mean a day on which the principal
national  securities  exchange  on which the shares are  listed or  admitted  to
trading is open for the transaction of business or, if the shares are not listed
or admitted to trading on any  national  securities  exchange,  on which the New
York  Stock  Exchange  or such  other  national  securities  exchange  as may be
selected by the Board of Directors of the Corporation is open. If the shares are
not publicly  held or not so listed or traded on any day within the period of 30
Trading Days  applicable  to the  determination  of Fair Market Value thereof as
aforesaid,  "Fair Market  Value"  shall mean the fair market  value  thereof per
share as determined in good faith by the Board of Directors of the  Corporation.
In either case referred to in the foregoing sentence,  the determination of Fair
Market Value shall be described in a statement  filed with the  Secretary of the
Corporation.

Section 8.  Consolidation,  Merger,  etc.

     In case  the  Corporation  shall  enter  into  any  consolidation,  merger,
combination  or other  transaction  in which  the  shares  of  Common  Stock are
exchanged for or changed into other stock or  securities,  cash and/or any other
property,  then  in any  such  case  each  outstanding  share  of  Participating
Preferred  Stock shall at the same time be  similarly  exchanged  for or changed
into the  aggregate  amount of stock,  securities,  cash and/or  other  property
(payable in like  kind),  as the case may be, for which or into which each share
of Common  Stock is changed or exchanged

                                       8
<PAGE>

multiplied  by the highest of the Vote  Multiple,  the Dividend  Multiple or the
Liquidation  Multiple  in effect  immediately  prior to such  event.

Section 9. Effective Time of Adjustments.

     (A)  Adjustments  to the  Participating  Preferred  Stock  required  by the
provisions of this Certificate of Designations shall be effective as of the time
at which the event requiring such adjustments  occurs.

     (B) The  Corporation  shall give prompt  written notice to the Rights Agent
and each holder of a share of Participating Preferred Stock of the effect of any
adjustment to the voting  rights,  dividend  rights or rights upon  liquidation,
dissolution  or winding up of the  Corporation  of such  shares  required by the
provisions of this  Certificate of Designations.  Notwithstanding  the foregoing
sentence,  the failure of the  Corporation  to give such notice shall not affect
the  validity  of or  the  force  or  effect  of or  the  requirement  for  such
adjustment.

Section 10. No Redemption.

     The shares of Participating  Preferred Stock shall not be redeemable at the
option of the Corporation or any holder thereof.  Notwithstanding  the foregoing
sentence of this Section,  the Corporation  may acquire shares of  Participating
Preferred  Stock in any other manner  permitted by law, the  provisions  of this
Certificate of Designations and the Restated Certificate of Incorporation of the
Corporation.

Section 11. Ranking.

     Unless otherwise  provided in the Restated  Certificate of Incorporation of
the Corporation or a Certificate of Designations relating to a subsequent series
of preferred stock of the Corporation,  the Participating  Preferred Stock shall
rank junior to all other series of the  Corporation's  preferred stock as to the
payment of dividends and the distribution of assets on liquidation,  dissolution
or winding up and senior to the Common Stock.

Section 12.  Amendment.

     At  any  time  when  any  shares  of  Participating   Preferred  Stock  are
outstanding, the provisions of this Certificate of Designations and the Restated
Certificate  of  Incorporation  of the  Corporation  shall not be amended in any
manner  which would  adversely  affect the rights,  privileges  or powers of the
Participating  Preferred  Stock  without,  in  addition  to any  other  vote  of
stockholders  required by law, the affirmative vote of the holders of two-thirds
or more of the  outstanding  shares of  Participating  Preferred  Stock,  voting
together  as a  single  class.

Section 13. Fractional  Shares.

     Participating  Preferred  Stock may be issued in  fractions of a share that
shall entitle the holder, in proportion to such holder's  fractional  shares, to
exercise voting rights, receive distributions,  participate in distributions and
have the  benefit  of all other  rights of holders  of  Participating  Preferred
Stock.

                                       9

<PAGE>

     IN WITNESS WHEREOF, Oregon Steel Mills, Inc. has caused this Certificate of
Designations to be signed and attested this 28 day of December 1999.

                                   OREGON STEEL MILLS, INC.


                                   By: /s/ L. Ray Adams
                                       -----------------------------------------
                                   Name:   L. Ray Adams
                                   Title:  Vice President of Finance and
                                           Chief Financial Officer

ATTEST:

/s/ LaNelle F. Lee
-------------------------------
Name:   LaNelle F. Lee
Title:  Secretary

                                       10