<PAGE>

                                                                     Exhibit 4.1

                         RIBOZYME PHARMACEUTICALS, INC.

                             2001 STOCK OPTION PLAN


SECTION 1.  PURPOSE

     This plan shall be known as the "RPI 2001 STOCK  OPTION PLAN" (the "Plan").
The purpose of the Plan is to promote the interests of Ribozyme Pharmaceuticals,
Inc. (the "Company") and its Subsidiaries and the Company's stockholders by (i)
attracting and retaining key officers, employees, and directors of, and
consultants to, the Company and its Subsidiaries and any future Affiliates; (ii)
motivating such individuals by means of performance-related incentives to
achieve long-range performance goals, (iii) enabling such individuals to
participate in the long-term growth and financial success of the Company, (iv)
encouraging ownership of stock in the Company by such individuals, and (v)
linking their compensation to the long-term interests of the Company and its
stockholders. With respect to any Options granted under the Plan that are
intended to comply with the requirements of "performance-based compensation"
under Section 162(m) of the Code, the Plan shall be interpreted in a manner
consistent with such requirements.

SECTION 2.  DEFINITIONS

     As used in the Plan, the following terms shall have the meanings set forth
below:

            (a) "AFFILIATE" shall mean (i) any entity that, directly or
     indirectly, is controlled by the Company, (ii) any entity in which the
     Company has a significant equity interest, (iii) an affiliate of the
     Company, as defined in Rule 12b-2 promulgated under Section 12 of the
     Exchange Act, and (iv) any entity in which the Company has at least twenty
     percent (20%) of the combined voting power of the entity's outstanding
     voting securities, in each case as designated by the Board as being a
     participating employer in the Plan.

            (b) "BOARD" shall mean the board of directors of the Company.

            (c) "CHANGE IN CONTROL" shall mean, unless otherwise defined in the
     applicable Option Agreement, any of the following events:

                (i)   An acquisition (other than directly from the Company) of
            any voting securities of the Company (the "Voting Securities") by
            any "Person" (as the term Person is used for purposes of Section 13
            (d) or 14(d) of the Securities Exchange Act of 1934, as amended (the
            "Exchange Act")) immediately after which such Person has "Beneficial
            Ownership" (within the meaning of Rule 13d-3 promulgated under the
            Exchange Act) of fifty percent (50%) or more of the

                                      -1-
<PAGE>

            combined voting power of the then outstanding Voting Securities;
            provided, however, that in determining whether a Change in Control
            has occurred, Voting Securities which are acquired in a "Non-Control
            Acquisition" (as hereinafter defined) shall not constitute an
            acquisition which would cause a Change in Control. A "Non-Control
            Acquisition" shall mean an acquisition by (i) an employee benefit
            plan (or a trust forming a part thereof) maintained by (A) the
            Company or (B) any subsidiary or (ii) the Company or any Subsidiary;

                (ii)  The individuals who, as of the date hereof, are members of
            the Board (the "Incumbent Board"), cease for any reason to
            constitute at least two-thirds of the Board; provided, however, that
            if the election or nomination for election by the Company's
            stockholders of any new director was approved by a vote of at least
            two-thirds of the Incumbent Board, such new director shall, for
            purposes of this Agreement, be considered as a member of the
            Incumbent Board; provided, further, however, that no individual
            shall be considered a member of the Incumbent Board if (1) such
            individual initially assumed office as a result of either an actual
            or threatened "Election Contest" (as described in Rule 14a-11
            promulgated under the Exchange Act) or other actual or threatened
            solicitation of proxies or consents by or on behalf of a Person
            other than the Board (a "Proxy Contest") including by reason of any
            agreement intended to avoid or settle any Election Contest or Proxy
            Contest or (2) such individual was designated by a Person who has
            entered into an agreement with the Company to effect a transaction
            described in clause (i) or (iii) of this paragraph; or

                (iii) Approval by stockholders of the Company of:

                      (A)   A merger, consolidation or reorganization involving
                the Company, unless,

                            (1)    The stockholders of the Company immediately
                      before such merger, consolidation or reorganization, own,
                      directly or indirectly, immediately following such merger,
                      consolidation or reorganization, at least seventy-five
                      percent (75%) of the combined voting power of the
                      outstanding Voting Securities of the corporation (the
                      "Surviving Corporation") in substantially the same
                      proportion as their ownership of the Voting Securities
                      immediately before such merger, consolidation or
                      reorganization;

                            (2)    The individuals who were members of the
                      Incumbent Board immediately prior to the execution of the
                      agreement providing for such merger, consolidation or
                      reorganization constitute at least two-thirds of the
                      members of the board of directors of the Surviving
                      Corporation; and

                                      -2-
<PAGE>

                            (3)    no Person (other than the Company, any
                      Subsidiary, any employee benefit plan (or any trust
                      forming a part thereof) maintained by the Company, the
                      Surviving Corporation or any Subsidiary, or any Person
                      who, immediately prior to such merger, consolidation or
                      reorganization, had Beneficial Ownership of fifty percent
                      (50%) or more of the then outstanding Voting Securities)
                      has Beneficial Ownership of fifty percent (50%) or more of
                      the combined voting power of the Surviving Corporation's
                      then outstanding Voting Securities.

                      (B)   A complete liquidation or dissolution of the
               Company; or

                      (C)   An agreement for the sale or other disposition of
               all or substantially all of the assets of the Company to any
               Person (other than a transfer to a Subsidiary)

          Notwithstanding the foregoing, a Change in Control shall not be deemed
     to occur solely because any Person (the "Subject Person") acquired
     Beneficial Ownership of more than the permitted amount of the outstanding
     Voting Securities as a result of the acquisition of Voting Securities by
     the Company which, by reducing the number of Voting Securities outstanding,
     increased the proportional number of shares Beneficially Owned by the
     Subject Person, provided that if a Change in Control would occur (but for
     the operation of this sentence) as a result of the acquisition of Voting
     Securities by the Company, and after such share acquisition by the Company,
     the Subject Person becomes the Beneficial Owner of any additional Voting
     Securities Beneficially Owned by the Subject Person, then a Change in
     Control shall occur.

          (d)  "CODE" shall mean the Internal Revenue Code of 1986, as amended
     from time to time.

          (e)  "COMMITTEE" shall mean a committee of the Board composed of not
     less than two Non-Employee Directors, each of whom shall be a "Non-Employee
     Director" for purposes of Exchange Act Section 16 and Rule 16b-3 thereunder
     and an "outside director" for purposes of Section 162(m) and the
     regulations promulgated under the Code.

          (f)  "CONSULTANT" shall mean any consultant to the Company or its
     Subsidiaries or Affiliates.

          (g)  "DIRECTOR" shall mean a member of the Board.

          (h)  "DISABILITY" shall mean, unless otherwise defined in the
     applicable Option Agreement, a disability that would qualify as a total and
     permanent disability under the Company's then current long-term disability
     plan.

                                      -3-
<PAGE>

          (i) "EMPLOYEE" shall mean a current or prospective officer or employee
     of the Company or of any Subsidiary or Affiliate.

          (j) "EXCHANGE ACT" shall mean the Securities Exchange Act of 1934, as
     amended from time to time.

          (k) "FAIR MARKET VALUE" with respect to the Shares, shall mean, for
     purposes of a grant of an Option as of any date, (i) the closing sales
     price of the Shares on any exchange on which the shares are traded, on such
     date, or in the absence of reported sales on such date, the closing sales
     price on the immediately preceding date on which sales were reported or
     (ii) in the event there is no public market for the Shares on such date,
     the fair market value as determined, in good faith, by the Committee in its
     sole discretion, and for purposes of a sale of a Share as of any date, the
     actual sales price on that date.

          (l) "INCENTIVE STOCK OPTION" shall mean an option to purchase Shares
     from the Company that is granted under Section 6 of the Plan and that is
     intended to meet the requirements of Section 422 of the Code or any
     successor provision thereto.

          (o) "NON-QUALIFIED STOCK OPTION" shall mean an option to purchase
     Shares from the Company that is granted under Section 6 of the Plan and is
     not intended to be an Incentive Stock Option.

          (p) "NON-EMPLOYEE DIRECTOR" shall mean a member of the Board who is
     not an officer or employee of the Company or any Subsidiary or Affiliate.

          (q) "OPTION" shall mean an Incentive Stock Option or a Non-Qualified
     Stock Option.

          (r) "OPTION AGREEMENT" shall mean any written agreement, contract, or
     other instrument or document evidencing any Option, which may, but need
     not, be executed or acknowledged by a Participant.

          (s) "OPTION PRICE" shall mean the purchase price payable to purchase
     one Share upon the exercise of an Option.

          (t) "OUTSIDE DIRECTOR" means, with respect to the grant of an Option,
     a member of the Board then serving on the Committee.

          (u) "PARTICIPANT" shall mean any Employee, Director, Consultant or
     other person who receives an Option under the Plan.

          (v) "PERSON" shall mean any individual, corporation, partnership,
     limited liability company, associate, joint-stock company, trust,
     unincorporated organization, government or political subdivision thereof or
     other entity.

                                      -4-
<PAGE>

          (w)  "RETIREMENT" shall mean, unless otherwise defined in the
     applicable Option Agreement, retirement of a Participant from the employ or
     service of the Company or any of its Subsidiaries or Affiliates in
     accordance with the terms of the applicable Company retirement plan or, if
     a Participant is not covered by any such plan, retirement on or after such
     Participant's 65th birthday.

          (x)  "SEC' shall mean the Securities and Exchange Commission or any
     successor thereto.

          (y)  "SECTION 16" shall mean Section 16 of the Exchange Act and the
     rules promulgated thereunder and any successor provision thereto as in
     effect from time to time.

          (z)  "SECTION 162 (M)" shall mean Section 162 (m) of the Code and the
     regulations promulgated thereunder and any successor or provision thereto
     as in effect from time to time.

          (aa) "SHARES" shall mean shares of the Common Stock, $0.01 par value,
     of the Company.

          (bb) "SUBSIDIARY" shall mean any Person (other than the Company) of
     which a majority of its voting power or its equity securities or equity
     interest is owned directly or indirectly by the Company.

SECTION 3.  ADMINISTRATION

     3.1  Authority of Committee. The Plan shall be administered by the
          ----------------------
Committee, which shall be appointed by and serve at the pleasure of the Board;
provided, however, with respect to Options to Outside Directors, all references
in the Plan to the Committee shall be deemed to be references to the Board.
Subject to the terms of the Plan and applicable law, and in addition to other
express powers and authorizations conferred on the Committee by the Plan, the
Committee shall have full power and authority in its discretion to: (i)
designate Participants; (ii) determine the type or types of Options to be
granted to a Participant; (iii) determine the number of Shares to be covered by,
or with respect to which payments, rights, or other matters are to be calculated
in connection with Options; (iv) determine the timing, terms, and conditions of
any Option; (v) accelerate the time at which all or any part of an Option may be
settled or exercised; (vi) determine whether, to what extent, and under what
circumstances Options may be settled or exercised in cash, Shares, other
securities, other Options or other property, or canceled, forfeited, or
suspended and the method or methods by which Options may be settled, exercised,
canceled, forfeited, or suspended; (vii) determine whether, to what extent, and
under what circumstances cash, Shares, other securities, other Options, other
property, and other amounts payable with respect to an Option shall be deferred
either automatically or at the election of the holder thereof or of the
Committee; (viii) interpret and administer the Plan and any instrument or
agreement relating to, or Option made under, the Plan; (ix) except to the extent
prohibited by Section 6.2,

                                      -5-
<PAGE>

amend or modify the terms of any Option at or after grant with the consent of
the holder of the Option; (x) establish, amend, suspend, or waive such rules and
regulations and appoint such agents as it shall deem appropriate for the proper
administration of the Plan; and (xi) make any other determination and take any
other action that the Committee deems necessary or desirable for the
administration of the Plan, subject to the exclusive authority of the Board
under Section 10 hereunder to amend or terminate the Plan.

     3.2  Committee Discretion Binding. Unless otherwise expressly provided in
          ----------------------------
the Plan, all designations, determinations, interpretations, and other decisions
under or with respect to the Plan or any Option shall be within the sole
discretion of the Committee, may be made at any time and shall be final,
conclusive, and binding upon all Persons, including the Company, any Subsidiary
or Affiliate, any Participant and any holder or beneficiary of any Option.

     3.3  Action by the Committee. The Committee shall select one of its members
          -----------------------
as its Chairperson and shall hold its meetings at such times and places and in
such manner as it may determine. A majority of its members shall constitute a
quorum. All determinations of the Committee shall be made by not less than a
majority of its members. Any decision or determination reduced to writing and
signed by all of the members of the Committee shall be fully effective as if it
had been made by a majority vote at a meeting duly called and held. The exercise
of an Option or receipt of an Option shall be effective only if an Option
Agreement shall have been duly executed and delivered on behalf of the Company
following the grant of the Option or other Option. The Committee may appoint a
Secretary and may make such rules and regulations for the conduct of its
business, as it shall deem advisable.

     3.4  Delegation. Subject to the terms of the Plan and applicable law, the
          ----------
Committee may delegate to one or more officers or managers of the Company or of
any Subsidiary or Affiliate, or to a Committee of such officers or managers, the
authority, subject to such terms and limitations as the Committee shall
determine, to grant Options to, or to cancel, modify or waive rights with
respect to, or to alter, discontinue, suspend, or terminate Options held by
Participants who are not officers or directors of the Company for purposes of
Section 16 or who are otherwise not subject to such Section.

     3.5  No Liability. No member of the Board or Committee shall be liable for
          ------------
any action taken or determination made in good faith with respect to the Plan or
any Option granted hereunder.

SECTION 4.  SHARES AVAILABLE FOR OPTIONS

     4.1  Shares Available. Subject to the provisions of Section 4.2 hereof, the
          ----------------
stock to be subject to Options under the Plan shall be the Shares of the Company
and the maximum number of Shares with respect to which Options may be granted
under the Plan shall be 1,000,000. Notwithstanding the foregoing and subject to
adjustment as provided in Section 4.2, the maximum number of Shares with respect
to which Awards may be granted under the Plan shall be increased by the number
of Shares with

                                      -6-
<PAGE>

respect to which Options or other Awards were granted under the 1996 Plan, as of
the effective date of this Plan, but which terminate, expire unexercised, or are
settled for cash, forfeited or canceled without the delivery of Shares under the
terms of such Plans after the effective date of this Plan.

     If, after the effective date of the Plan, any Shares covered by an Option
granted under this Plan, or to which such an Option relates, are forfeited, or
if such an Option is settled for cash or otherwise terminates, expires
unexercised, or is canceled without the delivery of Shares, then the Shares
covered by such Option, or to which such Option relates, or the number of Shares
otherwise counted against the aggregate number of Shares with respect to which
Options may be granted, to the extent of any such settlement, forfeiture,
termination, expiration, or cancellation, shall again become Shares with respect
to which Options may be granted. In the event that any Option or other Option
granted hereunder is exercised through the delivery of Shares or in the event
that withholding tax liabilities arising from such Option are satisfied by the
withholding of Shares by the Company, the number of Shares available for Options
under the Plan shall be increased by the number of Shares so surrendered or
withheld.

     4.2  Adjustments. In the event that the Committee determines that any
          -----------
dividend or other distribution (whether in the form of cash, Shares, other
securities, or other property), recapitalization, stock split, reverse stock
split, reorganization, merger, consolidation, split-up, spin-off, combination,
repurchase, or exchange of Shares or other securities of the Company, issuance
of warrants or other rights to purchase Shares or other securities of the
Company, or other similar corporate transaction or event affects the Shares such
that an adjustment is determined by the Committee, in its sole discretion, to be
appropriate, then the Committee shall, in such manner as it may deem equitable
(and, with respect to Incentive Stock Options, in such manner as is consistent
with Section 422 of the Code and the regulations thereunder) : (i) adjust any or
all of (1) the aggregate number of Shares or other securities of the Company (or
number and kind of other securities or property) with respect to which Options
may be granted under the Plan; (2) the number of Shares or other securities of
the Company (or number and kind of other securities or property) subject to
outstanding Options under the Plan; and (3) the grant or exercise price with
respect to any Option under the Plan, provided that the number of shares subject
to any Option shall always be a whole number; (ii) if deemed appropriate,
provide for an equivalent Option in respect of securities of the surviving
entity of any merger, consolidation or other transaction or event having a
similar effect; or (iii) if deemed appropriate, make provision for a cash
payment to the holder of an outstanding Option.

     4.3  Substitute Options. Any Shares issued by the Company as Substitute
          ------------------
Options in connection with the assumption or substitution of outstanding grants
from any acquired corporation shall not reduce the Shares available for Options
under the Plan.

     4.4  Sources of Shares Deliverable Under Options. Any Shares delivered
          -------------------------------------------
pursuant to an Option may consist, in whole or in part, of authorized and
unissued Shares or of issued Shares that have been reacquired by the Company.

                                      -7-
<PAGE>

SECTION 5.  ELIGIBILITY

     Any Employee, Director or Consultant shall be eligible to be designated a
Participant; provided, however, that Outside Directors shall only be eligible to
receive Options granted consistent with Section 7.

SECTION 6.  STOCK OPTIONS

     6.1  Grant. Subject to the provisions of the Plan, the Committee shall have
          -----
sole and complete authority to determine the Participants to whom Options shall
be granted, the number of Shares subject to each Option, the exercise price and
the conditions and limitations applicable to the exercise of each Option. The
Committee shall have the authority to grant Incentive Stock Options, or to grant
Non-Qualified Stock Options, or to grant both types of Options. In the case of
Incentive Stock Options, the terms and conditions of such grants shall be
subject to and comply with such rules as may be prescribed by Section 422 of the
Code, as from time to time amended, and any regulations implementing such
statute. A person who has been granted an Option under this Plan may be granted
additional Options under the Plan if the Committee shall so determine; provided,
however, that to the extent the aggregate Fair Market Value (determined at the
time the Incentive Stock Option related thereto is granted) of the Shares with
respect to which all Incentive Stock Options related to such Option are
exercisable for the first time by an Employee during any calendar year (under
all plans described in subsection (d) of Section 422 of the Code of the Company
and its Subsidiaries) exceeds $100,000 (or such higher amount as is permitted in
the future under Section 422(d) of the Code, such Options shall be treated as
Non-Qualified Stock Options.

     6.2  Price. The Committee in its sole discretion shall establish the Option
          -----
Price at the time each Option is granted. Except in the case of Substitute
Options, the Option Price of an Option may not be less than 100% of the Fair
Market Value of the Shares with respect to which the Option is granted on the
date of grant of such Option. Notwithstanding the foregoing and except as
permitted by the provisions of Section 4.2 and Section 10 hereof, the Committee
shall not have the power to (i) amend the terms of previously granted Options to
reduce the Option Price of such Options, or (ii) cancel such Options and grant
substitute Options with a lower Option Price than the canceled Options.

     6.3  Term. Subject to the Committee's authority under Section 3.1 and the
          ----
provisions of Section 6.5, each Option and all rights and obligations thereunder
shall expire on the date determined by the Committee and specified in the Option
Agreement. The Committee shall be under no duty to provide terms of like
duration for Options granted under the Plan. Notwithstanding the foregoing, no
Option shall be exercisable after the expiration of ten (10) years from the date
such Option was granted.

     6.4  Exercise.
          --------

          (a) Each Option shall be exercisable at such times and subject to such
     terms and conditions as the Committee may, in its sole discretion, specify
     in the applicable

                                      -8-
<PAGE>

     Option Agreement or thereafter. The Committee shall have full and complete
     authority to determine, subject to Section 6.5 herein, whether an Option
     will be exercisable in full at any time or from time to time during the
     tern of the Option, or to provide for the exercise thereof in such
     installments, upon the occurrence of such events and at such times during
     the term of the Option as the Committee may determine.

          (b) The Committee may impose such conditions with respect to the
     exercise of Options, including without limitation, any relating to the
     application of federal, state or foreign securities laws or the Code, as it
     may deem necessary or advisable. The exercise of any Option granted
     hereunder shall be effective only at such time as the sale of Shares
     pursuant to such exercise will not violate any state or federal securities
     or other laws.

          (c) An Option may be exercised in whole or in part at any time, with
     respect to whole Shares only, within the period permitted thereunder for
     the exercise thereof, and shall be exercised by written notice of intent to
     exercise the Option, delivered to the Company at its principal office, and
     payment in full to the Company at the direction of the Committee of the
     amount of the Option Price for the number of Shares with respect to which
     the Option is then being exercised. The exercise of an Option shall result
     in the termination of the other to the extent of the number of Shares with
     respect to which the Option is exercised.

          (d) Payment of the Option Price shall be made in cash or cash
     equivalents, or, at the discretion of the Committee, (i) in whole Shares
     valued at the Fair Market Value of such Shares on the date of exercise (or
     next succeeding trading date, if the date of exercise is not a trading
     date), together with any applicable withholding taxes, or (ii) by a
     combination of such cash (or cash equivalents) and such Shares; provided,
     however, that the optionee shall not be entitled to tender Shares pursuant
     to successive, substantially simultaneous exercises of an Option or any
     other stock option of the Company. Subject to applicable securities laws,
     an Option may also be exercised by delivering a notice of exercise of the
     Option and simultaneously selling the Shares thereby acquired, pursuant to
     a brokerage or similar agreement approved in advance by proper officers of
     the Company, using the proceeds of such sale as payment of the Option
     Price, together with any applicable withholding taxes. Until the optionee
     has been issued the Shares subject to such exercise, he or she shall
     possess no rights as a stockholder with respect to such Shares.


     6.5  Ten Percent Stock Rule. Notwithstanding any other provisions in the
          ----------------------
Plan, if at the time an Option is otherwise to be granted pursuant to the Plan
the optionee or rights holder owns directly or indirectly (within the meaning of
Section 424(d) of the Code) Shares of the Company possessing more than ten
percent (10%) of the total combined voting power of all classes of Stock of the
Company or its parent or Subsidiary or Affiliate corporations (within the
meaning of Section 422 (b) (6) of the Code), then any Incentive Stock Option to
be granted to such optionee or rights holder pursuant to the Plan shall satisfy
the requirement of Section 422(c) (5) of the Code, and the Option Price shall be
not less than 110% of the Fair Market Value of the

                                      -9-
<PAGE>

Shares of the Company, and such Option by its terms shall not be exercisable
after the expiration of five (5) years from the date such Option is granted.

SECTION 7.  NON-EMPLOYEE DIRECTOR AND OUTSIDE DIRECTOR OPTIONS

     7.1  The Board may provide that all or a portion of a Non-Employee
Director's annual retainer, meeting fees and/or other Options or compensation as
determined by the Board, be payable (either automatically or at the election of
a Non-Employee Director) in the form of Non-Qualified Stock Options. The Board
shall determine the terms and conditions of any such Options, including the
terms and conditions which shall apply upon a termination of the Non-Employee
Director's service as a member of the Board, and shall have full power and
authority in its discretion to administer such Options, subject to the terms of
the Plan and applicable law.

     7.2  The Board may also grant Options to Outside Directors pursuant to the
terms of the Plan. With respect to such Options, all references in the Plan to
the Committee shall be deemed to be references to the Board.

SECTION 8.  TERMINATION OF EMPLOYMENT

     The Committee shall have the full power and authority to determine the
terms and conditions that shall apply to any Option upon a termination of
employment with the Company, its Subsidiaries and Affiliates, including a
termination by the Company with or without cause, by a Participant voluntarily,
or by reason of death, Disability or Retirement, and may provide such terms and
conditions in the Option Agreement or in such rules and regulations as it may
prescribe.

SECTION 9.  CHANGE IN CONTROL

     Upon a Change in Control, to the extent permitted by applicable law:  (i)
any surviving or acquiring corporation shall assume any Options outstanding
under the Plan or shall substitute similar Options (including an option to
acquire the same consideration paid to the stockholders in the transaction
described in this subsection 10(b)) for those outstanding under the Plan, or
(ii) such Options shall continue in full force and effect.  In the event any
surviving or acquiring corporation refuses to assume such Options, or to
substitute similar options for those outstanding under the Plan, then, with
respect to Options held by persons then performing services as Employees,
Directors or Consultants, the time during which such Options may be exercised
shall be accelerated prior to such event and the Options shall be terminated if
not exercised after such acceleration and at or prior to such event.

SECTION 10. AMENDMENT AND TERMINATION

     10.1  Amendments to the Plan. The Board may amend, alter, suspend,
           ----------------------
discontinue, or terminate the Plan or any portion thereof at any time; provided
that no such amendment, alteration, suspension, discontinuation or termination
shall be made without stockholder approval

                                      -10-
<PAGE>

if such approval is necessary to comply with any tax or regulatory requirement
for which or with which the Board deems it necessary or desirable to comply.

     10.2 Amendments to Options. Subject to the restrictions of Section 6.2, the
          ---------------------
Committee may waive any conditions or rights under, amend any terms of, or
alter, suspend, discontinue, cancel or terminate, any Option theretofore
granted, prospectively or retroactively; provided that any such waiver,
amendment, alteration, suspension, discontinuance, cancellation or termination
that would adversely affect the rights of any Participant or any holder or
beneficiary of any Option theretofore granted shall not to that extent be
effective without the consent of the affected Participant, holder, or
beneficiary.

     10.3 Adjustments of Options Upon the Occurrence of Certain Unusual or
          ----------------------------------------------------------------
Nonrecurring Events. The Committee is hereby authorized to make adjustments in
-------------------
the terms and conditions of, and the criteria included in, Options in
recognition of unusual or nonrecurring events (including, without limitation,
the events described in Section 4.2 hereof) affecting the Company, any
Subsidiary or Affiliate, or the financial statements of the Company or any
Subsidiary or Affiliate, or of changes in applicable laws, regulations, or
accounting principles, whenever the Committee determines that such adjustments
are appropriate in order to prevent dilution or enlargement of the benefits or
potential benefits intended to be made available under the Plan.

SECTION 11.  GENERAL PROVISIONS

     11.1 Limited Transferability of Options.  Except as otherwise provided in
          ----------------------------------
the Plan, no Option shall be assigned, alienated, pledged, attached, sold or
otherwise transferred or encumbered by a Participant, except by will or the laws
of descent and distribution and/or as may be provided by the Committee in its
discretion, at or after grant, in the Option Agreement. No transfer of an Option
by will or by laws of descent and distribution shall be effective to bind the
Company unless the Company shall have been furnished with written notice thereof
and an authenticated copy of the will and/or such other evidence as the
Committee may deem necessary or appropriate to establish the validity of the
transfer.

     11.2 No Rights to Options.  No Person shall have any claim to be granted
          --------------------
any Option, and there is no obligation for uniformity of treatment of
Participants or holders or beneficiaries of Options. The terms and conditions of
Options need not be the same with respect to each Participant.

     11.4 Share Certificates.  All certificates for Shares or other securities
          ------------------
of the Company or any Subsidiary or Affiliate delivered under the Plan pursuant
to any Option or the exercise thereof shall be subject to such stop transfer
orders and other restrictions as the Committee may deem advisable under the Plan
or the rules, regulations and other requirements of the SEC or any state
securities commission or regulatory authority, any stock exchange or other
market upon which such Shares or other securities are then listed, and any
applicable Federal or state laws, and the Committee may cause a legend or
legends to be put on any such certificates to make appropriate reference to such
restrictions.

                                      -11-
<PAGE>

     11.5   Withholding.  A Participant may be required to pay to the Company or
            -----------
any Subsidiary or Affiliate and the Company or any Subsidiary or Affiliate shall
have the right and is hereby authorized to withhold from any Option, from any
payment due or transfer made under any Option or under the Plan, or from any
compensation or other amount owing to a Participant the amount (in cash, Shares,
other securities, other Options or other property) of any applicable withholding
or other taxes in respect of an Option, its exercise, or any payment or transfer
under an Option or under the Plan and to take such other action as may be
necessary in the opinion of the Company to satisfy all obligations for the
payment of such taxes.

     11.6   Option Agreements. Each Option hereunder shall be evidenced by an
            -----------------
Option Agreement that shall be delivered to the Participant and may specify the
terms and conditions of the Option and any rules applicable thereto. In the
event of a conflict between the terms of the Plan and any Option Agreement, the
terms of the Plan shall prevail.

     11.7   No Limit on Other Compensation Arrangements. Nothing contained in
            -------------------------------------------
the Plan shall prevent the Company or any Subsidiary or Affiliate from adopting
or continuing in effect other compensation arrangements, which may, but need
not, provide for the grant of Options.

     11.8   No Right to Employment. The grant of an Option shall not be
            ----------------------
construed as giving a Participant the right to be retained in the employ of the
Company or any Subsidiary or Affiliate. Further, the Company or a Subsidiary or
Affiliate may at any time dismiss a Participant from employment, free from any
liability or any claim under the Plan, unless otherwise expressly provided in an
Option Agreement.

     11.9   No Rights as Stockholder. Subject to the provisions of the Plan and
            ------------------------
the applicable Option Agreement, no Participant or holder or beneficiary of any
Option shall have any rights as a stockholder with respect to any Shares to be
distributed under the Plan until such person has become a holder of such Shares.

     11.10  Governing Law. The validity, construction and effect of the Plan
            -------------
and any rules and regulations relating to the Plan and any Option Agreement
shall be determined in accordance with the laws of the State of Colorado without
giving effect to conflicts of laws principles.

     11.11  Severability. If any provision of the Plan or any Option Agreement
            ------------
is, or becomes, or is deemed to be invalid, illegal, or unenforceable in any
jurisdiction or as to any Person or Option, or would disqualify the Plan or any
Option under any law deemed applicable by the Committee, such provision shall be
construed or deemed amended to conform to the applicable laws, or if it cannot
be construed or deemed amended without, in the determination of the Committee,
materially altering the intent of the Plan or the Option, such provision shall
be stricken as to such jurisdiction, Person or Option and the remainder of the
Plan and any such Option shall remain in full force and effect.

     11.12  Other Laws. The Committee may refuse to issue or transfer any
            ----------
Shares or other consideration under an Option if, acting in its sole discretion,
it determines that the issuance or transfer of such Shares or such other
consideration might violate any applicable law or regulation

                                      -12-
<PAGE>

(including applicable non-U.S. laws or regulations) or entitle the Company to
recover the same under Exchange Act Section 16 (b), and any payment tendered to
the Company by a Participant, other holder or beneficiary in connection with the
exercise of such Option shall be promptly refunded to the relevant Participant,
holder, or beneficiary.

     11.13  No Trust or Fund Created.  Neither the Plan nor any Option shall
            ------------------------
create or be construed to create a trust or separate fund of any kind or a
fiduciary relationship between the Company or any Subsidiary or Affiliate and a
Participant or any other Person. To the extent that any Person acquires a right
to receive payments from the Company or any Subsidiary or Affiliate pursuant to
an Option, such right shall be no greater than the right of any unsecured
general creditor of the Company or any Subsidiary or Affiliate.

     11.14  No Fractional Shares.  No fractional Shares shall be issued or
            --------------------
delivered pursuant to the Plan or any Option, and the Committee shall determine
whether cash, other securities, or other property shall be paid or transferred
in lieu of any fractional Shares or whether such fractional Shares or any rights
thereto shall be canceled, terminated or otherwise eliminated.

     11.15  Headings.  Headings are given to the sections and subsections of the
            --------
Plan solely as a convenience to facilitate reference. Such headings shall not be
deemed in any way material or relevant to the construction or interpretation of
the Plan or any provision thereof.

SECTION 12.  TERM OF THE PLAN

     12.1   Effective Date. The Plan shall be effective as of March 22, 2001
            --------------
provided it is approved and ratified by the Company's stockholders on or prior
to December 31, 2001.

     12.2   Expiration Date. No new Options shall be granted under the Plan
            ---------------
after the tenth (10th) anniversary of the Effective Date. Unless otherwise
expressly provided in the Plan or in an applicable Option Agreement, any Option
granted hereunder may, and the authority of the Board or the Committee to amend,
alter, adjust, suspend, discontinue, or terminate any such Option or to waive
any conditions or rights under any such Option shall, continue after the tenth
(10th) anniversary of the Effective Date.

                                      -13-