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                                                                EXHIBIT (10)(rr)



                    SOUTH TEXAS DRILLING & EXPLORATION, INC.
                                 1999 STOCK PLAN


         1.   Purpose. This 1999 Stock Plan (the "Plan") is intended to provide
incentives (a) to the officers and employees of South Texas Drilling &
Exploration, Inc. (the "Company"), its parent (if any) and any present or future
subsidiaries of the Company (collectively, "Related Corporations"), by providing
them with opportunities to purchase stock in the Company pursuant to options
granted hereunder which qualify as "incentive stock options" under Section
422A(b) of the Internal Revenue Code of 1986 (the "Code") ("ISO" or "ISOs"); (b)
to directors, officers, employees and consultants of the Company and Related
Corporations, or any other person or entity, including persons providing regular
services to the Company or Related Corporations ("Other Person or Entity"), by
providing them with opportunities to purchase stock in the Company pursuant to
options granted hereunder which do not qualify as ISOs ("Non-Qualified Option"
or "Non-Qualified Options"); and (c) to outside directors by providing each of
them with a grant of five-year options to purchase 10,000 shares of Common Stock
upon becoming a director of the Company and thereafter by providing each of them
with annual grants of five-year options to purchase 5,000 shares of Common Stock
("Outside Directors' Options"). Anything in this Plan to the contrary
notwithstanding, Stock Rights (as defined below) shall not be granted or awarded
hereunder to any administrator or administrators if such grant, award or
purchase would cause such administrator or administrators not to satisfy the
"disinterested person" requirements of Rule 16b-3, or any successor or amended
rule ("Rule 16b-3"), promulgated by the Securities and Exchange Commission under
the Securities Exchange Act of 1934, as amended (the "1934 Act").

         ISOs, Non-Qualified Options and Outside Directors' Options are referred
to hereafter individually as an "Option" and collectively as "Options." Options
are referred to hereafter as "Stock Rights." Recipients of such Stock Rights are
hereafter referred to individually as an "Optionee" and collectively as
"Optionees." As used herein, the terms "parent" and "subsidiary" mean "parent
corporation" and "subsidiary corporation" respectively, as those terms are
defined in Section 425 of the Code.

         2.   Administration of the Plan. The Plan shall be administered (i) to
the extent required by Rule 16b-3, by an administrator or administrators in
compliance with Rule 16b-3, and (ii) in all other cases, by such administrator
or administrators as the Board of Directors (the "Board") may designate
(collectively, the "Administrators"). Subject to the terms of the Plan, the
applicable Administrator shall have the authority to (i) determine the employees
of the Company and Related Corporations (from among the class of employees
eligible under paragraph 1 to receive ISOs) to whom ISOs may be granted and to
determine (from among the class of individuals and entities eligible under
paragraph 1 to receive Non-Qualified Options) to whom Non-Qualified Options may
be granted; (ii) determine the time or times at which Options may be granted;
(iii) determine the option price of shares subject to each Option (subject to
the requirements of paragraph 4 with respect to ISOs and paragraph 5 with
respect to Non-Qualified Options); (iv) determine whether each Option granted
shall be an ISO or a Non-Qualified Option; (v) determine the time or times when
each Option shall become exercisable and the duration of the exercise period
(subject to paragraph 4 with respect to ISOs and paragraph 5 with respect to
Non-Qualified Options); (vi) determine whether restrictions such as repurchase
options are to be imposed on shares subject to Stock Rights and the nature of
such restrictions, if any; and (vii) interpret the Plan and prescribe and
rescind rules and regulations relating to it; however, neither the Board nor the
applicable






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Administrator shall have any authority to determine whether or when an outside
director shall receive or exercise Outside Directors' Options (or to determine
the exercise price of such Outside Directors' Options) other than to ensure
compliance with the terms of the Plan with respect to Outside Directors'
Options. With respect to persons subject to Section 16 of the 1934 Act,
transactions under the Plan are intended to comply with all applicable
conditions of Rule 16b-3. To the extent any provision of the Plan or action by
the applicable Administrator fails to so comply, it shall be deemed null and
void, to the extent permitted by law and deemed advisable by the applicable
Administrator. The interpretation and construction by the applicable
Administrator of any provisions of the Plan or of any Stock Right granted under
it shall be final unless otherwise determined by the Board. Administrators or
the Board may from time to time adopt such rules and regulations for carrying
out the Plan as they may deem best. No member of the Board, any Administrator
nor the Company shall be liable for any action or determination made in good
faith with respect to the Plan or any Stock Right granted under it.

         3.   Stock. The stock subject to the Stock Rights shall be authorized
but unissued shares of the Company's Common Stock, par value $.10 per share (the
"Common Stock"), or shares of Common Stock reacquired by the Company in any
manner. The aggregate number of shares of Common Stock which may be issued
pursuant to the Plan is 650,000; provided, however, that in no event shall the
number of shares of Common Stock subject to, and issued upon the exercise of,
ISOs exceed 650,000 in the aggregate; and provided, further that the maximum
number of shares of Common Stock issuable under the Plan to any employee of the
Company in any calendar year shall not exceed 650,000. The number of shares
authorized for the grant of Stock Rights under the Plan shall be subject to
adjustment as provided in paragraph 8. If any Option or any other Stock Right
granted under the Plan shall expire or terminate for any reason without having
been exercised in full or shall cease for any reason to be exercisable in whole
or in part, or if the Company shall reacquire any unvested shares issued
pursuant to any Stock Right, the unpurchased shares subject to such Options or
Stock Rights and any unvested shares so reacquired by the Company shall again be
available for grants of Stock Rights under the Plan to the extent permitted by
Rule 16b-3.

         4.   ISO Provisions. Any of the following provisions shall have no
force or effect if its inclusion in the Plan is not necessary for Options issued
as ISOs to qualify as ISOs pursuant to the Code and the regulations issued
thereunder.

              A.   Grant of ISO. All ISOs shall be granted under the Plan within
ten (10) years of the date of the Plan's adoption by the Board or the date the
Plan receives the requisite shareholder approval, whichever is earlier.


              B.   Minimum Option Price for ISOs.


                   (i) The price per share specified in the agreement relating
to each ISO granted under the Plan shall not be less than the fair market value
per share of Common Stock on the date of such grant. In the case of an ISO to be
granted to an employee owning stock representing more than ten percent of the
total combined voting power of all classes of stock of the Company or any
Related Corporation, the price per share specified in the agreement relating to
such ISO shall not be less than 110 percent of the fair market value per share
of Common Stock on the date of grant.

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                   (ii) In no event shall the aggregate fair market value
(determined at the time an ISO is granted) of Common Stock for which ISOs
granted to any employee are exercisable for the first time by such employee
during any calendar year (under all stock option plans of the Company and any
Related Corporation) exceed $100,000.

                   (iii) If, at the time an ISO is granted under the Plan, the
Company's Common Stock is publicly traded, "fair market value" shall be
determined as of the last business day for which the prices or quotes discussed
in this sentence are available prior to the date such Option is granted and
shall mean (a) the last reported sales price of the Common Stock on the
principal national securities exchange on which the Common Stock is traded, if
the Common Stock is then traded on a national securities exchange; or (b) the
last reported sale price (on that date) of the Common Stock on the NASDAQ
National Market List, if the Common Stock is not then traded on a national
securities exchange; or (c) the closing bid price (or the average of bid prices)
last quoted (on that date) by an established quotation service for
over-the-counter securities, if the Common Stock is not reported on the NASDAQ
National Market List. However, if the Common Stock is not publicly traded at the
time an ISO is granted under the Plan, "fair market value" shall be deemed to be
the fair market value of the Common Stock as determined by the applicable
Administrator after taking into consideration all factors which it deems
appropriate, including, without limitation, recent sale and offer prices of the
Common Stock in private transactions negotiated at arm's length.

              C.   Duration of ISOs. Subject to earlier termination as provided
in subparagraphs F and G hereunder, each ISO shall expire on the date specified
by the applicable Administrator, but not more than (i) ten years from the date
of grant in the case of ISOs generally, and (ii) five years from the date of
grant in the case of ISOs granted to an employee owning stock possessing more
than ten percent of the total combined voting power of all classes of stock of
the Company or any Related Corporation. Subject to the foregoing provisions and
such earlier termination as provided in said subparagraphs F and G, the term of
each ISO shall be the term set forth in the original instrument granting such
ISO, except with respect to any part of such ISO that is converted into a
Non-Qualified Option pursuant to subparagraph K below.

              D.   Eligible Employees. ISOs may be granted to any employee of
the Company or any Related Corporation. Those officers and directors of the
Company who are not employees may not be granted ISOs under the Plan.

              E.   Acceleration of Exercise of ISOs. The Administrator shall
not, without the consent of the Optionee, accelerate the exercise date of any
installment of any ISO granted to any employee (and not previously converted
into a Non-Qualified Option pursuant to subparagraph K below) if such
acceleration would violate the annual vesting limitation contained in Section
422A(d) of the Code, as described in subparagraph B(ii) hereinabove.

              F.   Effect of Termination of Employment on ISOs. If an ISO
Optionee ceases to be employed by the Company or any Related Corporation other
than by reason of death or disability (as such term is defined in subparagraph G
hereunder), any ISO granted to such Optionee within the six-month period
immediately preceding such termination shall be cancelled forthwith.

                                    PAGE -3-             STOCX - 1999 STOCK PLAN


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With respect to any ISOs granted to such Optionee more than six months prior to
such termination, no further installments of such ISOs shall become exercisable
and his ISOs shall terminate after the passage of 90 days from the date of
termination of his employment, but in no event later than on their specified
expiration dates, except to the extent that such ISOs (or unexercised
installments thereof) have been converted into Non-Qualified Options pursuant to
subparagraph K below. Leave of absence with the written approval of the
applicable Administrator shall not be considered an interruption of employment
under the Plan, provided that such written approval contractually obligates the
Company or any Related Corporation to continue the employment of the employee
after the approved period of absence. Employment shall also be considered as
continuing uninterrupted during any other bona fide leave of absence (such as
those attributable to illness, military obligations or governmental service)
provided that the period of such leave does not exceed 90 days or, if longer,
any period during which such Optionee's right to reemployment is guaranteed by
statute. ISOs granted under the Plan shall not be affected by any change of
employment within or among the Company and Related Corporations, so long as the
Optionee continues to be an employee of the Company or any Related Corporation.

              G.   Effect of Death or Disability on ISOs. If an Optionee ceases
to be employed by the Company or any Related Corporation by reason of his death,
any ISO of his may be exercised, to the extent of the number of shares with
respect to which he could have exercised it on the date of his death, by his
estate, personal representative or beneficiary who has acquired the ISO by will
or by the laws of descent and distribution, at any time prior to the earlier of
the date specified in the ISO agreement, the ISO's specified expiration date or
one year of the death of the Optionee.

              If an Optionee ceases to be employed by the Company and all
Related Corporations by reason of his disability, he shall have the right to
exercise any ISO held by him on the date of termination of employment, to the
extent of the number of shares with respect to which he could have exercised it
on that date, at any time prior to the earlier of the date specified in the ISO
agreement, the ISO's specified expiration date or one year from the date of the
termination of the Optionee's employment. For the purposes of the Plan, the
term "disability" shall mean "permanent and total disability" as defined in
Section 22(e)(3) of the Code or successor statute.

              H.   Adjustments. Any adjustment made pursuant to paragraphs 8(A)
or (B) with respect to ISOs shall be made only after the applicable
Administrator, after consulting with counsel for the Company, determines whether
such adjustments would constitute a "modification" of such ISOs (as that term is
defined in Section 425 of the Code) or would cause any adverse tax consequences
for the holders of such ISOs. If the applicable Administrator determines that
such adjustments made with respect to ISOs would constitute a modification of
such ISOs, it may refrain from making such adjustments.

              I.   Notice to Company of Disqualifying Dispositions. Each
employee who receives an ISO must agree to notify the Company in writing
immediately after the employee makes a "disqualifying disposition" of any Common
Stock acquired pursuant to the exercise of an ISO. A "disqualifying disposition"
is any disposition (including any sale) of such Common Stock before the later of
(a) two years after the date the employee was granted the ISO, or (b) one year
after the date the employee acquired Common Stock by exercising the ISO. If the
employee has died before



                                    PAGE -4-             STOCX - 1999 STOCK PLAN



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such stock is sold, these holding period requirements do not apply and no
Disqualifying Disposition can occur thereafter.

              J.   Other Requirements. ISOs shall be issued subject to such
additional requirements as may be imposed from time to time by the Code or the
regulations issued thereunder.

              K.   Conversion of ISOs into Non-Qualified Options; Termination of
ISOs. The applicable Administrator, at the written request of any Optionee, may
in its discretion take such actions as may be necessary to convert such
Optionee's ISOs (or any installments or portions of installments thereof) that
have not been exercised on the date of conversion into Non-Qualified Options at
any time prior to the expiration of such ISOs, regardless of whether the
Optionee is an employee of the Company or a Related Corporation at the time of
such conversion. Such actions may include, but not be limited to, extending the
exercise period or reducing the exercise price of the appropriate installments
of such Options. At the time of such conversion, the applicable Administrator
(with the consent of the Optionee) may impose such conditions on the exercise of
the resulting Non-Qualified Options as the applicable Administrator in its
discretion may determine, provided that such conditions shall not be
inconsistent with the provisions of paragraph 5 or any other paragraph of the
Plan. Nothing in the Plan shall be deemed to give any Optionee the right to have
such Optionee's ISOs converted into Non-Qualified Options, and no such
conversion shall occur until and unless the Administrator takes appropriate
action. The applicable Administrator, with the consent of the Optionee, may also
terminate any portion of any ISO that has not been exercised at the time of such
termination.

         5.   Non-Qualified Options.


              A.   Minimum Option Price. The price per share specified in the
agreement relating to each Non-Qualified Option granted under the Plan shall not
be less than the fair market value per share of Common Stock on the date of such
grant. If, at the time a Non-Qualified Option is granted under the Plan, the
Company's Common Stock is publicly traded, "fair market value" shall be
determined as of the last business day for which the prices or quotes discussed
in this sentence are available prior to the date such Non-Qualified Option is
granted and shall mean (i) the last reported sales price of the Common Stock on
the principal national securities exchange on which the Common Stock is traded,
if the Common Stock is then traded on a national securities exchange; or (ii)
the last reported sale price (on that date) of the Common Stock on the NASDAQ
National Market List, if the Common Stock is not then traded on a national
securities exchange; or (iii) the closing bid price (or the average of bid
prices) last quoted (on that date) by an established quotation service for
over-the-counter securities, if the Common Stock is not reported on the NASDAQ
National Market List. However, if the Common Stock is not publicly traded at the
time a Non-Qualified Option is granted under the Plan, "fair market value" shall
be deemed to be the fair market value of the Common Stock as determined by the
applicable Administrator after taking into consideration all factors which it
deems appropriate, including, without limitation, recent sale and offer prices
of the Common Stock in private transactions negotiated at arm's length.


                                    PAGE -5-             STOCX - 1999 STOCK PLAN

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              B.   Duration of Non-Qualified Options. Each Non-Qualified Option
shall expire on the date specified by the applicable Administrator, but not more
than ten (10) years from the date of grant.

              C.   Vesting of Non-Qualified Options. Subject to any shorter or
longer vesting period and any termination provisions which the applicable
Administrator may impose, a Non-Qualified Option shall be exercisable as
follows: (i) 20% of the shares under the Non-Qualified Option shall be
exercisable one calendar year after the date of its grant, (ii) an additional
20% of the shares under the Non-Qualified Option shall be exercisable two
calendar years after the date of its grant, (iii) an additional 20% of the
shares under the Non-Qualified Option shall be exercisable three calendar years
after the date of its grant, (iv) an additional 20% of the shares under the
Non-Qualified Option shall be exercisable four calendar years after the date of
its grant, and (v) the last 20% of the shares under the Non-Qualified Option
shall be exercisable five calendar years after the date of its grant.

              D.   Maintain Non-ISO Status. If the applicable Administrator
determines to issue a Non-Qualified Option, it shall take whatever actions it
deems necessary, under Section 422A of the Code and the regulations promulgated
thereunder, to ensure that such Non-Qualified Option is not treated as an ISO.

         6.   Outside Directors' Options.

              A.   Grant. Upon becoming a director of the Company each outside
director shall receive an option to purchase 10,000 shares of Common Stock and
on June 15 of each calendar year after the date the Plan is approved by the
shareholders of the Company, each outside director then serving shall receive an
option to purchase 5,000 shares of Common Stock (individually, an "Outside
Director's Option," and collectively, "Outside Directors' Options"). In order to
phase in the Company's Outside Director's Option program, current outside
directors shall be granted an Outside Director's Option to purchase 10,000
shares on June 15, 1995.

              B.   Minimum Purchase Price. The exercise price per share of the
Outside Directors' Options shall not be less than the fair market value per
share of Common Stock on the date of such grant. If, at the time an Outside
Director's Option is granted under the Plan, the Company's Common Stock is
publicly traded, "fair market value" shall be determined as of the last business
day for which the prices or quotes discussed in this sentence are available
prior to the date such Outside Director's Option is granted and shall mean (i)
the last reported sales price of the Common Stock on the principal national
securities exchange on which the Common Stock is traded, if the Common Stock is
then traded on a national securities exchange; or (ii) the last reported sale
price (on that date) of the Common Stock on the NASDAQ National Market List, if
the Common Stock is not then traded on a national securities exchange; or (iii)
the closing bid price (or the average of bid prices) last quoted (on that date)
by an established quotation service for over-the-counter securities, if the
Common Stock is not reported on the NASDAQ National Market List. However, if the
Common Stock is not publicly traded at the time an Outside Director's Option is
granted under the Plan, "fair market value" shall be the average of the three
most recent sale and offer prices of the Common Stock in private transactions
negotiated at arm's length.

                                    PAGE -6-             STOCX - 1999 STOCK PLAN






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              C.   Duration of Outside Directors' Options. Each Outside
Director's Option shall expire five (5) years from the date of grant; otherwise,
an Outside Director's Option shall not be subject to forfeiture or termination.

              D.   Exercise. An outside director may exercise an Outside
Director's Option, if exercisable, by providing written notice to the Company
addressed to the Secretary of the Company at 9310 Broadway, Bldg. I, San
Antonio, Texas 78217. The written notice shall specify the number of options
being exercised, and by paying the full exercise price. The written notice shall
also include such written representations, warranties and covenants as may be
required by the Company, Company counsel or the applicable Administrator.

              E.   Maintain Non-ISO Status. The applicable Administrator shall
take whatever actions it deems necessary, under Section 422A of the Code and the
regulations promulgated thereunder, to ensure that any such Outside Director's
Option is not treated as an ISO.

              F.   Holding Period and Termination. An outside director may not
dispose of any shares acquired as a result of the exercise of an Outside
Director's Option until six months after the date of the "grant" of the Outside
Director's Option, as determined in accordance with Rule 16(b)-3. Upon the
termination of the Plan or the unavailability of shares of Common Stock for
issuance under the Plan, no additional Outside Directors' Options shall be
granted.

         7.   Written Agreements. Stock Rights shall be evidenced by instruments
(which need not be identical) in such forms as the applicable Administrator may
from time to time approve. Such instruments shall conform to such terms,
conditions and provisions as are applicable hereunder and may contain such other
terms and conditions and provisions as the applicable Administrator deems
advisable which are not inconsistent with the Plan, including restrictions
applicable to shares of Common Stock issuable upon exercise of Stock Rights. A
Stock Right may provide for acceleration of exercise in the event of a change in
control of the Company, in the discretion of and as defined by the applicable
Administrator. The applicable Administrator may from time to time confer
authority and responsibility on one or more of its own members and/or one or
more officers of the Company to execute and deliver such instruments. The proper
officers of the Company are authorized and directed to take any and all action
necessary or advisable from time to time to carry out the terms of such
instruments.

         8.   Adjustments. Upon the happening of any of the following described
events, an Optionee's rights with respect to Options granted to him hereunder,
shall be adjusted as hereinafter provided, unless otherwise specifically
provided, in addition or to the contrary, in the written agreement between the
recipient and the Company relating to such Stock Right.

              A.   Certain Corporate Events. In the event shares of Common Stock
shall be subdivided or combined into a greater or smaller number of shares or
if, upon a merger, consolidation, reorganization, split-up, liquidation,
combination, recapitalization or the like of the Company, the shares of Common
Stock shall be exchanged for other securities of the Company or of another
corporation, each grantee of a Stock Right shall be entitled, subject to the
conditions herein stated, to purchase (or have used for measurement purposes)
such number of shares of Common Stock or amount of other securities of the
Company or such other corporation as were


                                    PAGE -7-             STOCX - 1999 STOCK PLAN

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exchangeable for the number of shares of Common Stock which such grantee would
have been entitled to purchase (or have used for measurement purposes) except
for such action, and appropriate adjustments shall be made in the purchase price
per share to reflect such subdivision, combination or exchange.

              B.   Stock Dividends. In the event the Company shall issue any of
its shares as a stock dividend upon or with respect to the shares of stock of
the class which at the time shall be subject to a Stock Right hereunder, each
grantee upon exercising a Stock Right shall be entitled to receive (for the
purchase price paid upon such exercise) (or have used for measurement purposes)
the shares or other consideration as to which he is exercising his Stock Right
and, in addition thereto (at no additional cost), such number of shares of the
class or classes in which such stock dividend or dividends were declared or
paid, and such amount of cash in lieu of fractional shares, or other
consideration as he would have received if he had been the holder of the shares
as to which he is exercising (or which are used for measurement in connection
with) his Stock Right at all times between the date of grant of such Stock Right
and the date of its exercise.

              C.   New Securities. If any person or entity owning restricted
Common Stock obtained by exercise of a Stock Right made hereunder receives new
or additional or different shares or securities ("New Securities") in connection
with a corporate transaction described in subparagraph A above or a stock
dividend described in subparagraph B above as a result of owning such restricted
Common Stock, such New Securities shall be subject to all of the conditions and
restrictions applicable to the restricted Common Stock with respect to which
such New Securities were issued.

              D.   Cash Dividends. No adjustments shall be made for dividends
paid in cash or in property other than securities of the Company, unless
specified to the contrary by the applicable Administrator in the instrument
evidencing such Stock Right.

              E.   Fractional Shares. No fractional shares shall actually be
issued under the Plan. Any fractional shares which, but for this subparagraph E,
would have been issued to a grantee pursuant to a Stock Right shall be deemed to
have been issued and immediately sold to the Company for their fair market
value, and the grantee shall receive from the Company cash in lieu of such
fractional shares.

              F.   Adjustments. Upon the happening of any of the foregoing
events described in subparagraphs A or B above, the class and aggregate number
of shares set forth in paragraph 3 hereof that are subject to Stock Rights which
previously have been or subsequently may be granted under the Plan shall also be
appropriately adjusted to reflect the events described in such subparagraphs.
The Board shall determine the specific adjustments to be made under this
paragraph 8 and, subject to paragraph 4(H), its determination shall be
conclusive.

         9.   Means of Exercising Stock Rights. A Stock Right (or any part or
installment thereof) shall be exercised as specified in the written instrument
granting such Stock Right, which instrument may specify any legal method of
exercise. The holder of a Stock Right exercisable for shares shall not have the
rights of a shareholder with respect to the shares covered by his Stock Right
until the date of issuance of a stock certificate to him for such shares. Except
as expressly


                                    PAGE -8-             STOCX - 1999 STOCK PLAN

<PAGE>   9



provided above in paragraph 8 with respect to changes in capitalization and
stock dividends, no adjustment shall be made for dividends or similar rights for
which the record date is before the date such stock certificate is issued.

         10.  Transferability of Stock Rights. Except as otherwise provided in
the Plan, no Stock Right granted under the Plan shall be transferrable by an
Optionee other than by (i) will or the laws of descent and distribution, or (ii)
pursuant to a qualified domestic relations order as defined by the Code or
Title I of the Employee Retirement Income Security Act, or the rules thereunder.

         11.  Term of the Plan. This Plan was adopted by the Board as of April
21, 1995, effective as of May 1, 1995, subject to approval of the Plan by the
holders of a majority of the outstanding shares of the Company at the next
meeting of shareholders present in person or by proxy at the next meeting of
shareholders. Stock Rights may be granted under the Plan at any time on or after
May 1, 1995, even if prior to the date of shareholder approval of the Plan;
provided, however, that such date shall not be prior to the date on which the
applicable Administrator acts to approve the grant or award. If the requisite
shareholder approval is not obtained by April 21, 1996, any grants of ISOs under
the Plan and any grants of Stock Rights to officers and directors, as the case
may be, made prior to that date will be automatically rescinded, except in the
case of an ISO granted to Wm. Stacy Locke which, in such event, shall remain in
effect but without the benefits of this Plan.

         12.  Termination; Amendment. The Board may terminate or amend the Plan
in any respect at any time, except that (i) no amendment requiring shareholder
approval under provisions of the Code and related regulations relating to ISOs
or under Rule 16b-3 will be effective without approval of shareholders as
required and within the times set by such rules, and (ii) no amendment may be
made more than once every six (6) months to the provisions of the Plan dealing
with, related to, affecting or governing Outside Directors' Options (other than
those required to comport with changes in the Code, the Employee Retirement
Income Security Act, or the rules thereunder, or Rule 16b-3).

         13.  Application of Funds. The proceeds received by the Company from
the sale of shares pursuant to Stock Rights authorized under the Plan shall be
used for general corporate purposes.

         14.  Governmental Regulation. The Company's obligation to sell and
deliver shares of the Common Stock under this Plan is subject to the approval of
any governmental authority required in connection with the authorization,
issuance or sale of such shares.

         15.  Withholding of Additional Income Taxes. Upon the exercise of a
Non-Qualified Option, an Outside Director's Option, the making of a Purchase of
Common Stock for less than its fair market value, the making of a Disqualifying
Disposition (as defined in paragraph 4(I)), the vesting of restricted Common
Stock acquired on the exercise of a Stock Right hereunder, or any other event in
connection with a Stock Right, the Company, in accordance with Section 3402(a)
of the Code, may require the Optionee, purchaser, or holder or exerciser of a
Stock Right to pay additional withholding taxes in respect of the amount that is
considered compensation includable in such person's gross income.

                                    PAGE -9-             STOCX - 1999 STOCK PLAN

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         16.  Governing Law; Construction. The validity and construction of the
Plan and the instruments evidencing Stock Rights shall be governed by the laws
of the State of Texas. In construing this Plan, the singular shall include the
plural and the masculine gender shall include the feminine and neuter, unless
the context otherwise requires.


































                                   PAGE -10-             STOCX - 1999 STOCK PLAN









<PAGE>   11
                        INCENTIVE STOCK OPTION AGREEMENT







     THIS OPTION AGREEMENT is made as of the ____ day of _________, 1999, ("Date
of Grant") by and between SOUTH TEXAS DRILLING & EXPLORATION, INC., with its
principal place of business at 9310 Broadway, Building 1, San Antonio, Bexar
County, Texas (hereinafter called the "Company"), and __________________
(hereinafter called the "Employee"), an employee of Company.

     WHEREAS, the Company desires to afford the Employee an opportunity to
purchase shares of the $.1O par value voting common stock of the Company
(hereinafter called the "stock"), pursuant to and in accordance with the terms
and provisions of the Company's 1999 Stock Plan (hereinafter referred to as the
"Plan") and as hereinafter provided.

     NOW, THEREFORE, in consideration of the mutual covenants hereinafter set
forth and Employee's employment by the Company, the parties hereto agree as
follows:

     1. The Plan. This Option Agreement is made pursuant to and in accordance
with the terms and provisions of the Plan as adopted by the Board of Directors
of the Company on December 13, 1999, and subject to the approval by a vote of a
majority interest of the stockholders of the Company on or before December 13,
2000. Anything in this Option Agreement to the contrary notwithstanding, the
terms and provisions of the Plan, all of which are incorporated herein by
reference, shall be controlling in the event of any inconsistency herewith. By
signing this Agreement, the Employee acknowledges that he has received a copy of
the Plan.

     2. Grant of Option. The Company hereby irrevocably grants to the Employee
the right and option (hereinafter called the "Option") to purchase all of any
part of an aggregate of _______ shares of the stock (subject to adjustment as
provided in the Plan) on the terms and conditions hereinafter set forth. The
Date of the Grant of the Option is ______________.

     3. Purchase Price. The purchase price of the shares of the stock covered by
the


<PAGE>   12






Option shall be $_____ per share (subject to adjustment as provided in the
Plan), which the Company believes is in excess of the fair market value of the
stock as of the Date of the Grant.

     4. Time Option is Exercisable. Until this Option is terminated, the
Employee shall have the right to purchase all or a portion of the stock subject
to this Option at such times, and from time to time, as he might desire, subject
to the terms and provisions hereinafter set forth. There is no obligation on the
Employee to purchase any of the stock subject to the Option. The Option shall be
exercised as follows:

          (1) Twenty percent (20%) of the shares under Option shall become
exercisable on _______, 20__.

          (2) An additional twenty percent (20%) (being forty percent (40%) of
the total shares under Option) shall become exercisable ________, 20__, two
(2) years after the Date of Grant.

          (3) An additional twenty percent (20%) (being sixty percent (60%) of
the total shares under Option) shall become exercisable __________, 20__.

          (4) An additional twenty percent (20%) (being eighty percent (80%) of
the total shares under Option) shall become exercisable __________, 20__.

          (5) An additional twenty percent (20%) (being one hundred percent
(100%) of the total shares under Option) shall become exercisable _______, 20__.

     5. Exercise of Option. The Employee may exercise this Option by giving
written notice to the Company specifying the number of full shares to be
purchased and accompanied by payment of the full price thereof. No exercise of
the Option shall be complete and no stock shall be delivered to the Employee
prior to the time that the full purchase price for such stock has been paid. The
purchase price shall be paid in cash. During the lifetime of the Employee, the
Option

                               PAGE -2-     LITTLE - INCENTIVE STOCK OPTION AGMT


<PAGE>   13



may not be exercised by any person (including the spouse of the Employee) other
than by the Employee. Upon the death of the Employee, the Option may be
exercised by the personal representative, legatees of heirs of the Employee
until the earlier to occur of (a) the termination of the Option or the Plan by
their terms or (b) the date one (1) year after the date of death of the
Employee.

     6. Nontransferability of Option. This Option is not transferable except by
Will or by the laws of descent and distribution. This Option may not be
assigned, transferred, pledged or hypothecated in any manner and shall not be
subject to any form of execution, attachment or similar process. Any attempted
assignment, transfer, pledge, hypothecation or other disposition of this Option
contrary to the provisions of this Agreement and the Plan, or the levy of any
execution, attachment or similar process upon the Option, shall be null and void
and of no effect.

     7. Stockholder Rights. The Employee shall not have any of the rights of a
stockholder merely because of his ownership of the Option granted by this
Agreement.

     8. Employment. The grant of this Option shall not impose upon the Company
any obligation whatsoever to retain the Employee in its employ for any period.
This Option is personal to the Employee and may be exercised by him as provided
in the Plan only if he is continuously employed by the Company from the date of
the granting of this Option to the date of its exercise, except as otherwise
provided herein and in the Plan. Should such employment be terminated by the
Company (for any reason whatsoever or for no reason) or by the voluntary action
of the Employee for any reason (other than by reason of the death of the
Employee), this Option, to the extent that it has not been exercised, shall
terminate three (3) months after the date of termination of employment (the
"Termination Date") and shall not be exercised after the Termination Date.

                               PAGE -3-     LITTLE - INCENTIVE STOCK OPTION AGMT


<PAGE>   14



     9. Requirements of Law. If any law or regulation of the Securities and
Exchange Commission or any other federal or state commission or agency having
jurisdiction requires the Company or the Employee to take any action with
respect to the stock acquired by the exercise of this Option, then the date upon
which the company shall deliver the stock shall be postponed until full
compliance has been made with all such legal or regulatory requirements.
Further, at or before the time of the delivery of the stock, the Employee shall,
if requested by the Company, deliver to the Company his written statement that
he intends to hold the stock so acquired by him on exercise of this Option for
investment and not with a view to resale or other distribution thereof to the
public. Further, in the event the Company shall determine that, in compliance
with the Securities Act of 1933, as amended, or any other applicable federal or
state statute or regulation, it is necessary to register any of the shares of
stock with respect to which an exercise of this Option has been made, or to
qualify any such shares for exemption from any of such requirements, the Company
shall take such action at its own expense, but not until such action has been
completed shall the Option shares be delivered to the Employee.

     10. Tax Benefits. Under the terms of Sections 421 and 422A of the Code,
the Employee is entitled to certain federal income tax advantages upon exercise
of this incentive stock option. The tax benefits are available, however, only if
the Employee does not dispose of stock acquired pursuant to this Agreement
within two (2) years from the date the Option was granted nor within one (1)
year after the transfer of the shares to the Employee upon exercise of the
Option.

     IN WITNESS THEREOF, the Company has caused this Incentive Stock Option
Agreement to be executed by an authorized officer, and the Employee has hereunto
set his hand, all as of the day and year first above written.

                              PAGE -4-     LITTLE - INCENTIVE STOCK OPTION AGMT
<PAGE>   15







                              SOUTH TEXAS DRILLING & EXPLORATION, INC.


                              By:
                                 --------------------------------------



                              EMPLOYEE:


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






                              PAGE -5-     LITTLE - INCENTIVE STOCK OPTION AGMT