<PAGE>

                                                                   Exhibit 10.46

                                   PLUMAS BANK
                             1991 STOCK OPTION PLAN

1. PURPOSE

      The purpose of the 1991 Stock Option Plan is to strengthen Plumas Bank
(the "Bank") and those corporations which are or hereafter become subsidiary
corporations of the Bank by providing an additional means of attracting and
retaining competent managerial personnel and by providing to participating
officers and management level employees added incentive for high levels of
performance. The Plan seeks to accomplish these purposes and achieve these
results by providing a means whereby such officers and key employees may
purchase shares of the common stock of the Bank pursuant to options granted in
accordance with this Plan.

      Options granted pursuant to this Plan are intended to be "Incentive Stock
Options" within the meaning of Section 422A of the Internal Revenue Code of
1986, as amended from time to time (the "Code"), or "non-qualified" stock
options, as shall be determined and designated upon the grant of each option
hereunder.

2. ADMINISTRATION

      This Plan shall be administered by a committee (the "Stock Option
Committee") consisting of certain members of the Board of Directors who from
time to time shall be selected by the Board. Any action of the Stock Option
Committee with respect to the administration of the Plan shall be taken pursuant
to a majority vote, or to the unanimous written consent, of its members. If no
Stock Option Committee is selected, the Board of Directors as a whole shall act
as such Committee. Vacancies occurring in the membership of the Committee shall
be filled by appointment by the Board of Directors. With regard to the granting
of a stock option to a member of the Board of Directors or to a member of a
Stock Option Committee, such member must abstain from voting.

      Subject to the express provisions of the Plan, the Stock Option Committee
(or Board of Directors if applicable) shall have the authority to construe and
interpret the Plan, define the terms used therein, prescribe, amend, rescind
rules and regulations relating to administration of the Plan, and make all other
determinations necessary or advisable for administration of the Plan.
Determinations of the Stock Option Committee (or Board of Directors if
applicable) on matters referred to in this section shall be final and
conclusive.

<PAGE>

3. INCENTIVE STOCK OPTIONS

      (a) Incentive Stock Options granted under this Plan are intended to be
qualified under Section 422A of the Internal Revenue Code, as amended from time
to time (the "Code"). Each Incentive Stock Option Agreement shall contain such
terms and provisions as the Stock Option Committee may determine to be necessary
in order to qualify options granted thereunder as incentive stock options within
the meaning of Section 422A of the Code.

      (b) Full-time salaried officers and key employees of the Bank or of
subsidiary corporations (as that term is defined in Section 425 of the Code),
shall be eligible for selection to participate in the incentive stock option
portion of the Plan. No director of the Bank who is not also a full-time
salaried officer or key employee of the Bank or a subsidiary corporation, may be
granted an incentive stock option hereunder. Subject to the express provisions
of the Plan, the Stock Option Committee shall select from the eligible class of
employees and make recommendations to the Board of Directors concerning the
individuals to whom incentive stock options shall be granted, the terms and
provisions of the respective incentive stock option agreements, the times at
which such incentive stock options shall be granted, and the number of shares
subject to each incentive option. An individual who has been granted an
incentive stock option hereunder may, if he or she is otherwise eligible, be
granted additional incentive stock options if the Board of Directors shall so
determine.

      (c) The Board of Directors shall determine the individuals who shall
receive incentive stock options and the terms and provisions of the incentive
stock options, and shall grant such incentive stock options to such individuals.
Notwithstanding the above, however, the Board of Directors may delegate to the
Stock Option Committee the power to determine the individuals who shall receive
options, the terms and provisions of such incentive stock options to such
individuals.

      (d) Except as described in subsection (f) below, the Board of Directors or
the Stock Option Committee, if authorized, shall not grant an incentive stock
option to purchase shares of the Bank's common stock to any individual who, at
the time of the grant, owns stock possessing more than 10% of the total combined
voting power or value of all classes of stock of the Bank or its parent or
subsidiary corporation. The attribution rules of Section 425(d) of the Code
shall apply in the determination of ownership of stock for these purposes.

      (e) The aggregate fair market value (determined as of the time the
incentive stock option is granted) of stock with respect to which incentive
stock options are exercisable for the first time by an employee during any
calendar year (under any other incentive stock option plan of the Bank and

<PAGE>

its subsidiary corporations, if any) shall not exceed $100,000, plus any greater
amount as may be permitted under subsequent amendments to the Internal Revenue
Code of 1986.

      (f) The purchase price of stock subject to each incentive stock option
shall be determined by the Board of Directors (or the Stock Option Committee if
authorized), but shall not be less than one hundred percent (100%) of the fair
market value of such stock at the time such option is granted, except for
officers and key employees who at the time of the grant own more than 10 percent
of the total combined voting power of all classes of stock of the Bank or its
parent or subsidiary corporation (as defined in Section 422A of the Code), in
which case the purchase price of the stock shall not be less than 110 percent of
the fair market value of such stock at the time such option is granted and the
term of such option shall be for no more than 5 years. The fair market value of
such stock shall be determined in accordance with any reasonable valuation
method, including the valuation methods described in Treasury Regulation Section
20.2031-2. The purchase price of any shares purchased shall be paid in full in
cash at the time of each said purchase.

      (g) The number of shares subject to outstanding stock options (including
both incentive and non-qualified stock options) held by any single optionee may
not exceed ten percent (10%) of the total outstanding shares of the Bank's
common stock.

4. NON-QUALIFIED STOCK OPTIONS

      (a) All options granted which are (i) in excess of the fair market value
limitations set forth in Section 3(e) hereof, (ii) designated at the time of the
grant as "non-qualified", or (iii) intended to be incentive stock options but do
not meet the requirements of incentive stock options, shall be deemed
non-qualified stock options. Non-qualified stock options granted hereunder shall
be so designated in the Stock Option Agreement entered into between the Bank and
the Participant.

      (b) Directors, full-time salaried officers and key employees of the Bank
or of a subsidiary corporation shall be eligible for selection to participate in
the non-qualified stock option portion of the Plan. Subject to the express
provisions of the Plan, the Stock Option Committee shall (i) select from the
eligible class of individuals to whom non-qualified stock options shall be
granted, (ii) determine the discretionary terms and provisions of the respective
non-qualified stock option agreements (which need not be identical), (iii)
determine the times at which such non-qualified stock options shall be granted,
and (iv) determine the number of shares subject to each non-qualified stock
option. An individual who has been granted a non-qualified stock option may, if
he or she is

                                        3
<PAGE>

otherwise eligible, be granted additional non-qualified stock options if the
Board of Directors shall so determine.

      (c) The Board of Directors shall determine the individuals who shall
receive non-qualified stock options and the terms and provisions of the
non-qualified stock options, and shall grant such non-qualified stock options to
such individuals. Notwithstanding the above, however, the Board of Directors may
delegate to the Stock Option Committee the power to determine the individuals
who shall receive non-qualified stock options, the terms and provisions of such
non-qualified stock options, and to grant non-qualified stock options to such
individuals.

      (d) The purchase price of stock subject to each non-qualified stock option
shall be determined by the Board of Directors (or the Stock Option Committee, if
authorized), but shall not be less than one hundred percent (100%) of the fair
market value of such stock at the time such option is granted. The fair market
value of such stock shall be determined in accordance with any reasonable
valuation method, including the valuation methods described in Treasury
Regulation 20.2031-2. The purchase price of any shares purchased shall be paid
in full in cash at the time of each purchase.

      (e) The number of shares subject to outstanding stock options (including
both incentive and non-qualified and stock options) held by the single optionee
may not exceed ten percent (10%) of the total outstanding shares of the Bank's
common stock.

      Notwithstanding anything to the contrary contained herein, any option
grant to a director of the Bank pursuant to this Plan shall be made subject to
the following terms and conditions:

      (i)   Each non-employee director may be granted non-qualified stock
            options pursuant to this Plan to purchase a maximum of 3,000 shares
            of the Bank's common stock for all such options, and each employee
            director may be granted incentive stock options and non-qualified
            stock options pursuant to this Plan to purchase a maximum of 15,000
            shares of the Bank's common stock for all such options, subject to
            adjustments provided in Section 12 of this Plan;

      (ii)  Options granted shall vest and become exercisable as to 1/5 of the
            total number of option shares granted on the first anniversary date
            of the option grant, as to an additional 1/5 of the total number of
            option shares granted on the second anniversary date of the option
            grant, as to an additional 1/5 of the total number of option shares
            granted on the third anniversary date of the date of the option
            grant, as to an additional 1/5 of the total number of option shares
            granted on the fourth anniversary date of the date of the option
            grant and the remaining 1/5 of the total number of option shares on
            the fifth anniversary of the date of the option grant. Vesting of
            such

                                        4
<PAGE>

            options may accelerate in accordance with Section 13. If a director
            shall not on any anniversary purchase all the shares which such
            optionee is entitled to purchase, such optionee's right to purchase
            any shares not purchased on such anniversary shall continue until
            expiration or termination of such option,

      (iii) The term of any option shall be 10 years from the time of the option
            grant, and

      (iv)  The maximum aggregate number of shares which may be granted to, (i)
            non-employee directors pursuant to this Plan is 33,000, and (ii) to
            employee directors is 30,000. In the event that options granted
            under this paragraph to directors shall for any reason terminate,
            lapse, be forfeited or expire without being exercised, the shares
            subject to such unexercised options may be granted to directors
            subject to the limitations in this paragraph.

5. STOCK SUBJECT TO THE PLAN

      Subject to adjustments as provided in Section 12, hereof, the stock to be
offered under the Plan shall be shares of the Bank's authorized but unissued
common stock (hereinafter called "stock") and the aggregate amount of stock to
be delivered upon exercise of all options granted under this Plan shall not
exceed 97,950 shares (which amount may not exceed 30 percent of the total
outstanding shares of the same class and series of the Bank). If any option
shall be cancelled, surrendered or expire for any reason without having been
exercised in full, the underlying shares subject thereto shall again be
available for purposes of this Plan.

6. CONTINUATION OF EMPLOYMENT

      Nothing contained in the Plan (or in any option agreement) shall obligate
the Bank or any subsidiary corporation to employ any option holder ("Optionee")
for any period or interfere in any way with the right of the Bank or a
subsidiary corporation to reduce the Optionee's compensation. However, the Bank
may not change the terms of any option which would lessen the value of such
option without the approval of the Optionee.

7. EXERCISE OF OPTIONS

      No option shall be exercisable until all necessary regulatory and
shareholder approvals are obtained. Except as otherwise provided in this
section, each option shall be exercisable in such installments, which need not
be equal, and upon such contingencies as the Board of Directors (or the Stock
Option Committee, if authorized) shall determine, provided, however, that if an
Optionee shall not in any given installment period purchase all of the shares
which the Optionee is entitled to

                                        5
<PAGE>

purchase in such installment period, the Optionee's right to purchase any shares
not purchased in such installment period shall continue until expiration or
termination of such option. Fractional share interests shall be disregarded,
except that they may be accumulated. Not less than ten (10) shares may be
purchased under the option. Options may be exercised by written notice delivered
to the Bank stating the number of shares with respect to which the option is
being exercised, together with the full purchase price for such shares. Payment
of the option price in full, for the number of shares to be delivered, must be
made in cash. If the option is being exercised by any person other than the
Optionee, said notice shall be accompanied by proof, satisfactory to counsel for
the Bank, of the right of such person to exercise the option. Optionees will
have no rights as stockholders with respect to stock of the Bank subject to
their Stock Option Agreements until the date of issuance of stock certificates
to them.

8. NONTRANSFERABILITY OF OPTIONS

      Each option shall, by its terms, be nontransferable by the Optionee other
than by Will or the laws of descent and distribution, and shall be exercisable
during his or her lifetime only by the Optionee.

9. CESSATION OF DIRECTORSHIP OR EMPLOYMENT

      Except as provided in Section 10 and 20 hereof, if an Optionee ceases to
be a director of the Bank (with respect to an option granted to non-employee
director) or an employee (with respect to an option other than a non-employee
director option) of the Bank or a subsidiary corporation for any reason other
than his disability (as defined in Section 105(d)(4) of the Code) or death, the
Optionee's option shall expire 90 days after the date of termination of
directorship or employment. During the period after cessation of directorship or
employment, such option shall be exercisable only as to those installments, if
any, which have accrued and/or vested as of the date on which the Optionee
ceased to be a director or employed by the Bank or a subsidiary corporation.

10. TERMINATION OF EMPLOYMENT FOR CAUSE

      If the Stock Option Agreement so provides and if an Optionee's
directorship or employment by the Bank or a subsidiary corporation is terminated
for cause, the Optionee's option shall expire immediately, provided, however,
the Board of Directors may, in its sole discretion, within thirty (30) days of
such termination, reinstate the option by giving written notice of such
reinstatement to the

                                        6
<PAGE>

Optionee at the Optionee's last known address. In the event of reinstatement,
the Optionee may exercise the option only to such extent, for such time, and
upon such terms and conditions as if he had ceased to be a director or ceased to
be employed by the Bank or a subsidiary corporation upon the date of such
termination for a reason other than cause or death. Termination for cause shall
include, but not be limited to, termination for malfeasance or gross misfeasance
in the performance of duties or conviction of illegal activity in connection
therewith.

11. DISABILITY OR DEATH OF OPTIONEE

      If any Optionee dies while being a director or employee of the Bank or a
subsidiary corporation, the option shall expire one (1) year after the date of
such death, except as provided in Section 20 hereof. After such death but before
such expiration, the persons to whom the Optionee's rights under the option
shall have passed by Will or by the applicable laws of descent and distribution
or the executor or administrator of Optionee's estate shall have the right to
exercise such option to the extent that installments, if any, had accrued and/or
vested as of the date on which the Optionee ceased to be a director or employed
by the Bank or a subsidiary corporation.

      If the Optionee shall terminate his or her directorship or employment
because of disability (as defined in Section 105(d)(4) of the Internal Revenue
Code of 1986, as amended from time to time), the Optionee may exercise this
option to the extent he or she is entitled to do so at the date of termination,
at any time within one year of the date of termination, except as provided in
Section 20.

      If any Optionee dies or becomes disabled during the 90 day period referred
to in Section 9 hereof, the option shall expire one (1) year after the date of
such death or disability, except as provided in Section 20.

12. ADJUSTMENT UPON CHANGES IN CAPITALIZATION

      If the outstanding shares of the stock of the Bank are increased,
decreased, or changed into, or exchanged for a different number or kind of
shares or securities of the Bank through reorganization, merger,
recapitalization, reclassification, stock split, stock dividend, stock
consolidation, or otherwise, without consideration to the Bank, an appropriate
and proportionate adjustment shall be made in the number and kind of shares as
to which options may be granted. A corresponding adjustment changing the number
or kind of shares and the exercise price per share allocated to unexercised
options, or portions thereof, which shall have been granted prior to any such
change shall likewise be made. Any adjustment under the Section shall be made by
the Board of Directors,

                                        7
<PAGE>

whose determination as to what adjustments shall be made, and the extent
thereof, shall be final and conclusive. No fractional shares of stock shall be
issued or made available under the Plan on account of any such adjustment, and
fractional share-interests shall be disregarded, except that they may be
accumulated.

13. TERMINATING EVENTS

      A Terminating Event shall be defined as any one of the following events;
(i) dissolution or liquidation of the Bank, (ii) a reorganization, merger or
consolidation of the Bank with one or more corporations, the result of which (A)
the Bank is not the surviving corporation or (B) the Bank becomes a subsidiary
of another corporation (which shall be deemed to have occurred if another
corporation shall own directly or indirectly, over 80% of the aggregate voting
power of all outstanding equity securities of the Bank), (iii) a sale of
substantially all the assets of the Bank to another corporation, or (iv) a sale
of the equity securities of the Bank representing more than 80% of the aggregate
voting power of all outstanding equity securities of the Bank to any person or
entity, or any group of persons and/or entities acting in concert. Upon a
Terminating Event (i) the Bank shall deliver to each Optionee no less than 30
days prior to the Terminating Event, written notification of the Terminating
Event and the Optionee's right to exercise all options granted pursuant to this
Plan, whether or not vested under this Plan or applicable Stock Option
Agreement, and (ii) all outstanding options granted pursuant to this Plan shall
completely vest and become immediately exercisable as to all shares granted
pursuant to the option immediately prior to such Terminating Event. This right
of exercise shall be conditional upon the execution of a final plan of
dissolution or liquidation or a definitive agreement of consolidation or merger,
as appropriate. Upon the occurrence of the Terminating Event all outstanding
options and the Plan shall terminate, provided however that any outstanding
options not exercised as of the occurrence of the Terminating Event shall not
terminate if there is a successor corporation which assumes the outstanding
options or substitutes for such options, new options covering the stock of the
successor corporation with appropriate adjustments as to the number and kind of
shares and prices.

14. AMENDMENT AND TERMINATION

      The Board of Directors of the Bank may at any time suspend, amend, or
terminate the Plan and may, with the consent of the Optionee, make such
modification of the terms and conditions of

                                        8
<PAGE>

the option as it shall deem advisable; provided that, except as permitted under
the provisions of Sections 7, 12 and 13 hereof, no amendment or modification
which would:

      (a)   increase the maximum number of shares which may be purchased
            pursuant to options granted under the Plan either in the aggregate
            or by an individual,

      (b)   change the minimum option price;

      (c)   increase the maximum term of options provided for herein,

      (d)   permit options to be granted to anyone other than a director,
            full-time salaried officer (including a full-time salaried officer
            director) or key employee of the Bank or a subsidiary corporation;
            or

      (e)   change the conditions of an option grant to a director

may be adopted without the Bank having first obtained any necessary regulatory
approvals and shareholder approvals required by law.

      No option may be granted during any suspension or after termination of the
Plan. Amendment, suspension, or termination of the Plan shall not (except as
otherwise provided in Section 12 hereof), without the consent of the Optionee,
alter or impair any rights or obligation under any option theretofore granted.

15. TIME OF GRANTING OPTIONS

      The time an option is granted, sometimes referred to as the date of grant,
shall be the day of the action of the Board of Directors (or action of the Stock
Option Committee, if authorized) described in Sections 3(c) and 4(c) hereof;
provided, however, that if appropriate resolutions of the Board of Directors (or
the Stock Option Committee, if authorized) indicate that an option is granted as
of and on some future date, the time such option is granted shall be such future
date. If action by the Board of Directors (or the Stock Option Committee, if
authorized) is taken by unanimous written consent of its members, the action of
the Board of Directors (or the Stock Option Committee) shall be deemed to be at
the time the last Board (or Stock Option Committee) member signs the consent.

16. PRIVILEGES OF STOCK OWNERSHIP, SECURITIES LAW COMPLIANCE; NOTICE OF SALE

      No Optionee shall be entitled to the privileges of stock ownership as to
any shares of stock not actually issued. No shares shall be purchased upon the
exercise of any option unless and until all

                                        9
<PAGE>

then applicable requirements of any regulatory agencies having jurisdiction and
all applicable requirements of any exchanges upon which stock of the Bank may be
listed, shall have been fully complied with. The Optionee shall give the Bank
notice of any sale or disposition of any such shares not more than five (5) days
after such sale or disposition.

17. EFFECTIVE DATE OF THE PLAN

      The Plan shall be deemed adopted by the Board of Directors as of March 20,
1991, and shall be effective immediately subject to approval by the shareholders
of the Bank by vote of a majority of the outstanding shares represented and
voting at a meeting of shareholders and by a majority of the disinterested
shares represented and voting at the meeting, and the approval of the State
Banking Department.

18. TERMINATION

      Unless previously terminated by the Board of Directors, the Plan shall
terminate at the close of business on a date ten (10) years from the earlier of
the date of approval by the Bank's outstanding shares or the date of adoption of
this Plan by the Board of Directors. No options shall be granted under the Plan
thereafter, but such termination shall not affect any option theretofore
granted.

19. OPTION AGREEMENT

      Each option shall be evidenced by a written Stock Option Agreement
executed by the Bank and the Optionee and shall contain each of the provisions
and agreements herein specifically required to be contained therein, and such
other terms and conditions as are deemed desirable and are not inconsistent with
the Plan. Each Incentive Stock Option Agreement shall contain such terms and
provisions as the Stock Option Committee may determine to be necessary in order
to qualify such option as any incentive stock option within the meaning of
Section 422A of the Code.

20. OPTION PERIOD

      Each option and all rights or obligations thereunder shall expire on such
date as the Board of Directors (or the Stock Option Committee, if authorized)
may determine, but not later than ten (10) years from the date such option is
granted, and shall be subject to earlier termination as provided elsewhere in
the Plan.

                                       10
<PAGE>

21. EXCULPATION AND INDEMNIFICATION

      To the extent permitted by applicable law in effect from time to time, no
member of the Board of Directors or Stock Option Committee shall be liable for
any action or omission of any other member of the Board of Directors or Stock
Option Committee nor for any act or omission on the member's own part, except
the member's own willful misconduct or gross negligence. The Board of Directors
of the Bank and its subsidiary corporations shall pay expenses incurred by, and
satisfy a judgment or fine rendered or levied against, a present or former
director or member of the Stock Option Committee in any action brought by a
third party against such person (whether or not the Bank is joined as a party
defendant) to impose a liability or penalty on such person while a director or
member of the Stock Option Committee arising with respect to the Plan or
administration thereof or out of membership on the Stock Option Committee or of
the Bank, or all or any combination of the preceding; provided, the Board of
Directors determines in good faith that such director or member was acting in
good faith, within what such director or member reasonably believed to be the
scope of his or her employment or authority, and for a purpose which he or she
reasonably believed to be in the best interests of the Bank or its shareholders.
Payments authorized hereunder include amounts paid and expenses incurred in
settling any such action or threatened action. This Section does not apply to
any action instituted or maintained in the right of the Bank by a shareholder or
holder of a voting trust certificate representing shares of the Bank or any
subsidiary corporation thereof. The provisions of this Section shall apply to
the estate, executor, administrator, heirs, legatees or devisees of a director
or member of the Stock Option Committee, and the term "person" as used in this
Section shall include the estate, executor, administrator, heirs, legatees or
devisees of such person.

                                       11
<PAGE>

                       FIRST AMENDMENT TO THE PLUMAS BANK
                             1991 STOCK OPTION PLAN

This First Amendment to the Plumas Bank 1991 Stock Option Plan ("1991 Plan") was
approved by the Board of Directors of Plumas Bank on November 15, 2000.

The 1991 Plan is amended as follows:

1.    AMENDMENT OF SECTION 7. The third to the last sentence in Section 7 shall
      be amended in the entirety to read as follows:

            Payment of the option price in full, for the number of shares to be
            delivered, must be made in cash or subject to applicable law, with
            Bank common stock previously acquired by the optionee and held by
            the optionee for a period of at least six months.

2.    AMENDMENT OF SECTION 7. A new sentence shall be added after the sentence
      in the aforementioned amendment to read in the entirety as follows:

            The equivalent dollar value of shares used to effect a purchase
            shall be the fair market value of the shares on the date of the
            exercise.

/s/ W. E. ELLIOTT                                        Dated November 15, 2000
-----------------
 William E. Elliott, President & C.E.O.

                                       12