<PAGE>
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                                                                  EXHIBIT 10.270

                                 PROMISSORY NOTE

<TABLE>
<CAPTION>
 PRINCIPAL    LOAN DATE    MATURITY   LOAN NO  CALL/COLL  ACCOUNT  OFFICE  INITIALS
<S>           <C>         <C>         <C>      <C>        <C>      <C>     <C>
$400,000.00   04-16-2004  04-16-2009    9003              7326653   52680
</TABLE>

  References in the shaded area are for Lender's use only and do not limit the
  applicability of this document to any particular loan or item. Any item above
      containing " * * *" has been omitted due to text length limitations.

BORROWER:  READY MIX, INC.                  LENDER: NEVADA STATE BANK
           3430 E. FLAMINGO RD., SUITE 100          CORPORATE LENDING DEPARTMENT
           LAS VEGAS, NV 89121                      750 E. WARM SPRINGS ROAD
                                                    LAS VEGAS, NV 89119

<TABLE>
<S>                             <C>                       <C>
PRINCIPAL AMOUNT:$400,000.00    INTEREST RATE: 6.250%     DATE OF NOTE: APRIL 16, 2004
</TABLE>

PROMISE TO PAY. READY MIX, INC. ("BORROWER") PROMISES TO PAY TO NEVADA STATE
BANK ("LENDER"), OR ORDER, IN LAWFUL MONEY OF THE UNITED STATES OF AMERICA, THE
PRINCIPAL AMOUNT OF FOUR HUNDRED THOUSAND & 00/100 DOLLARS ($400,000.00),
TOGETHER WITH INTEREST AT THE RATE OF 6.250% PER ANNUM ON THE UNPAID PRINCIPAL
BALANCE FROM APRIL 16, 2004, UNTIL PAID IN FULL.

PAYMENT. BORROWER WILL PAY THIS LOAN IN 59 REGULAR PAYMENTS OF $3,449.60 EACH
AND ONE IRREGULAR LAST PAYMENT ESTIMATED AT $309,412.09. BORROWER'S FIRST
PAYMENT IS DUE MAY 16, 2004, AND ALL SUBSEQUENT PAYMENTS ARE DUE ON THE SAME DAY
OF EACH MONTH AFTER THAT. BORROWER'S FINAL PAYMENT WILL BE DUE ON APRIL 16,
2009, AND WILL BE FOR ALL PRINCIPAL AND ALL ACCRUED INTEREST NOT YET PAID.
PAYMENTS INCLUDE PRINCIPAL AND INTEREST. UNLESS OTHERWISE AGREED OR REQUIRED BY
APPLICABLE LAW, PAYMENTS WILL BE APPLIED FIRST TO ANY UNPAID COLLECTION COSTS;
THEN TO ANY LATE CHARGES; THEN TO ANY ACCRUED UNPAID INTEREST; AND THEN TO
PRINCIPAL. THE ANNUAL INTEREST RATE FOR THIS NOTE IS COMPUTED ON A 365/360
BASIS; THAT IS, BY APPLYING THE RATIO OF THE ANNUAL INTEREST RATE OVER A YEAR OF
360 DAYS, MULTIPLIED BY THE OUTSTANDING PRINCIPAL BALANCE, MULTIPLIED BY THE
ACTUAL NUMBER OF DAYS THE PRINCIPAL BALANCE IS OUTSTANDING. BORROWER WILL PAY
LENDER AT LENDER'S ADDRESS SHOWN ABOVE OR AT SUCH OTHER PLACE AS LENDER MAY
DESIGNATE IN WRITING.

PREPAYMENT PENALTY; MINIMUM INTEREST CHARGE. Borrower agrees that all loan fees
and other prepaid finance charges are earned fully as of the date of the loan
and will not be subject to refund upon early payment (whether voluntary or as a
result of default), except as otherwise required by law. In any event, even upon
full prepayment of this Note, Borrower understands that Lender is entitled to a
MINIMUM INTEREST CHARGE OF $50.00. UPON PREPAYMENT OF THIS NOTE, LENDER IS
ENTITLED TO THE FOLLOWING PREPAYMENT PENALTY: IN THE EVENT THE LOAN IS PREPAID
WITHIN THE FIRST FIVE YEARS OF EXECUTION OF THE PROMISSORY NOTE, BORROWER SHALL
PAY BANK A PREPAYMENT PENALTY AS FOLLOWS:

PREPAYMENT WITH THE 1ST YEAR - 5% OF THE PRINCIPAL BALANCE
PREPAYMENT WITH THE 2ND YEAR - 4% OF THE PRINCIPAL BALANCE
PREPAYMENT WITH THE 3RD YEAR - 3% OF THE PRINCIPAL BALANCE
PREPAYMENT WITH THE 4TH YEAR - 2% OF THE PRINCIPAL BALANCE
PREPAYMENT WITH THE 5TH YEAR - 1% OF THE PRINCIPAL BALANCE

AFTER THE 5TH YEAR FROM EXECUTION OF THE PROMISSORY NOTE, NO PREPAYMENT PENALTY
WILL BE ASSESSED. PREPAYMENTS WILL BE APPLIED TO THE LAST SUMS FALLING DUE.
Other than Borrower's obligation to pay any minimum interest charge and
prepayment penalty, Borrower may pay all or a portion of the amount owed earlier
than it is due. Early payments will not, unless agreed to by Lender in writing,
relieve Borrower of Borrower's obligation to continue to make payments under the
payment schedule. Rather, early payments will reduce the principal balance due
and may result in Borrower's making fewer payments. Borrower agrees not to send
Lender payments marked "paid in full", "without recourse", or similar language.
If Borrower sends such a payment, Lender may accept it without losing any of
Lender's rights under this Note, and Borrower will remain obligated to pay any
further amount owed to Lender. All written communications concerning disputed
amounts, including any check or other payment instrument that indicates that the
payment constitutes "payment in full" of the amount owed or that is tendered
with other conditions or limitations or as full satisfaction of a disputed
amount must be mailed or delivered to: Nevada State Bank, Commercial Loan
Servicing Department 3800, P. O. Box 990 Las Vegas, NV 89125-0990.

LATE CHARGE. If a payment is 10 days or more late, Borrower will be charged
5.000% OF THE REGULARLY SCHEDULED PAYMENT OR $25.00, WHICHEVER IS GREATER.

INTEREST AFTER DEFAULT. Upon default, including failure to pay upon final
maturity, Lender, at its option, may, if permitted under applicable law,
increase the interest rate on this Note 3.000 percentage points. The interest
rate will not exceed the maximum rate permitted by applicable law.

DEFAULT. Each of the following shall constitute an event of default ("Event of
Default") under this Note:

      PAYMENT DEFAULT. Borrower fails to make any payment when due under this
      Note.

      OTHER DEFAULTS. Borrower fails to comply with or to perform any other
      term, obligation, covenant or condition contained in this Note or in any
      of the related documents or to comply with or to perform any term,
      obligation, covenant or condition contained in any other agreement between
      Lender and Borrower.

      DEFAULT IN FAVOR OF THIRD PARTIES. Borrower or any Grantor defaults under
      any loan, extension of credit, security agreement, purchase or sales
      agreement, or any other agreement, in favor of any other creditor or
      person that may materially affect any of Borrower's property or Borrower's
      ability to repay this Note or perform Borrower's obligations under this
      Note or any of the related documents.

      FALSE STATEMENTS. Any warranty, representation or statement made or
      furnished to Lender by Borrower or on Borrower's behalf under this Note or
      the related documents is false or misleading in any material respect,
      either now or at the time made or furnished or becomes false or misleading
      at any time thereafter.

      INSOLVENCY. The dissolution or termination of Borrower's existence as a
      going business, the insolvency of Borrower, the appointment of a receiver
      for any part of Borrower's property, any assignment for the benefit of
      creditors, any type of creditor workout, or the commencement of any
      proceeding under any bankruptcy or insolvency laws by or against Borrower.

      CREDITOR OR FORFEITURE PROCEEDINGS. Commencement of foreclosure or
      forfeiture proceedings, whether by judicial proceeding, self-help,
      repossession or any other method, by any creditor of Borrower or by any
      governmental agency against any collateral securing the loan. This
      includes a garnishment of any of Borrower's accounts, including deposit
      accounts, with Lender. However, this Event of Default shall not apply if
      there is a good faith dispute by Borrower as to the validity or
      reasonableness of the claim which is the basis of the creditor or
      forfeiture proceeding and if Borrower gives Lender written notice of the
      creditor or forfeiture proceeding and deposits with Lender monies or a
      surety bond for the creditor or forfeiture proceeding, in an amount
      determined by Lender, in its sole discretion, as being an adequate reserve
      or bond for the dispute.

      EVENTS AFFECTING GUARANTOR. Any of the preceding events occurs with
      respect to any Guarantor of any of the indebtedness or any Guarantor dies
      or becomes incompetent, or revokes or disputes the validity of, or
      liability under, any guaranty of the indebtedness evidenced by this Note.
      In the event of a death, Lender, at its option, may, but shall not be
      required to, permit the Guarantor's estate to assume unconditionally the
      obligations arising under the guaranty in a manner satisfactory to Lender,
      and, in doing so, cure any Event of Default.

      CHANGE IN OWNERSHIP. Any change in ownership of twenty-five percent (25%)
      or more of the common stock of Borrower.

      ADVERSE CHANGE. A material adverse change occurs in Borrower's financial
      condition, or Lender believes the prospect of payment or performance of
      this Note is impaired.

      CURE PROVISIONS. If any default, other than a default in payment is
      curable and if Borrower has not been given a notice of a breach of the
      same provision of this Note within the preceding twelve (12) months, it
      may be cured (and no event of default will have occurred) if Borrower,
      after receiving written notice from Lender demanding cure of such default:
      (1) cures the default within ten (10) days; or (2) if the cure requires
      more than ten (10) days, immediately initiates steps which Lender deems in
      Lender's sole discretion to be sufficient to cure the default and
      thereafter continues and completes all reasonable and necessary steps
      sufficient to produce compliance as soon as reasonably practical.

LENDER'S RIGHTS. Upon default, Lender may declare the entire unpaid principal
balance on this Note and all accrued unpaid interest immediately due, and then
Borrower will pay that amount.

ATTORNEYS' FEES; EXPENSES. Lender may hire or pay someone else to help collect
this Note if Borrower does not pay. Borrower will pay Lender that amount. This
includes, subject to any limits under applicable law, Lender's attorneys' fees
and Lender's legal expenses, whether or not there is a lawsuit, including
attorneys' fees, expenses for bankruptcy proceedings (including efforts to
modify or vacate any automatic stay or injunction), and appeals. If not
prohibited by applicable law, Borrower also will pay any court costs, in
addition to all other sums provided by law.

GOVERNING LAW. THIS NOTE WILL BE GOVERNED BY, CONSTRUED AND ENFORCED IN
ACCORDANCE WITH FEDERAL LAW AND THE LAWS OF THE STATE OF NEVADA. THIS NOTE HAS
BEEN ACCEPTED BY LENDER IN THE STATE OF NEVADA.

<PAGE>

                                 PROMISSORY NOTE
LOAN NO: 9003                      (CONTINUED)                            PAGE 2

CHOICE OF VENUE. If there is a Lawsuit,Borrower agrees upon Lender's request to
submit to the jurisdiction of the courts of Clark County, State of Nevada.
(INITIAL HERE C.T.)

DISHONORED ITEM FEE. Borrower will pay a fee to Lender of $20.00 if Borrower
makes a payment on Borrower's loan and the check or preauthorized charge with
which Borrower pays is later dishonored.

RIGHT OF SETOFF. To the extent permitted by applicable law, Lender reserves a
right of setoff in all Borrower's accounts with Lender (whether checking,
savings, or some other account). This includes all accounts Borrower holds
jointly with someone else and all accounts Borrower may open in the future.
However, this does not include any IRA or Keogh accounts, or any trust accounts
for which setoff would be prohibited by law. Borrower authorizes Lender, to the
extent permitted by applicable law, to charge or setoff all sums owing on the
indebtedness against any and all such accounts, and, at Lender's option, to
administratively freeze all such accounts to allow Lender to protect Lender's
charge and setoff rights provided in this paragraph.

COLLATERAL. Borrower acknowledges this Note is secured by a Deed of Trust of
even date.

ARBITRATION DISCLOSURES.

      1.    ARBITRATION IS FINAL AND BINDING ON THE PARTIES AND SUBJECT TO ONLY
            VERY LIMITED REVIEW BY A COURT.

      2.    IN ARBITRATION THE PARTIES ARE WAIVING THEIR RIGHT TO LITIGATE IN
            COURT, INCLUDING THEIR RIGHT TO A JURY TRIAL.

      3.    DISCOVERY IN ARBITRATION IS MORE LIMITED THAN DISCOVERY IN COURT.

      4.    ARBITRATORS ARE NOT REQUIRED TO INCLUDE FACTUAL FINDINGS OR LEGAL
            REASONING IN THEIR AWARDS. THE RIGHT TO APPEAL OR SEEK MODIFICATION
            OF ARBITRATORS' RULINGS IS VERY LIMITED.

      5.    A PANEL OF ARBITRATORS MIGHT INCLUDE AN ARBITRATOR WHO IS OR WAS
            AFFILIATED WITH THE BANKING INDUSTRY.


      6.    ARBITRATION WILL APPLY TO ALL DISPUTES BETWEEN THE PARTIES, NOT JUST
            THOSE CONCERNING THE AGREEMENT.

      7.    IF YOU HAVE QUESTIONS ABOUT ARBITRATION, CONSULT YOUR ATTORNEY OR
            THE AMERICAN ARBITRATION ASSOCIATION.

      (a) Any claim or controversy ("Dispute") between or among the parties and
      their employees, agents, affiliates, and assigns, including, but not
      limited to, Disputes arising out of or relating to this agreement, this
      arbitration provision ("arbitration clause"), or any related agreements or
      instruments relating hereto or delivered in connection herewith ("Related
      Agreements"), and including, but not limited to, a Dispute based on or
      arising from an alleged tort, shall at the request of any party be
      resolved by binding arbitration in accordance with the applicable
      arbitration rules of the American Arbitration Association (the
      "Administrator"). The provisions of this arbitration clause shall survive
      any termination, amendment, or expiration of this agreement or Related
      Agreements. The provisions of this arbitration clause shall supersede any
      prior arbitration agreement between or among the parties.

      (b) The arbitration proceedings shall be conducted in a city mutually
      agreed by the parties. Absent such an agreement, arbitration will be
      conducted in Las Vegas, Nevada or such other place as may be determined by
      the Administrator. The Administrator and the arbitrator(s) shall have the
      authority to the extent practicable to take any action to require the
      arbitration proceeding to be completed and the arbitrator(s)' award issued
      within 150 days of the filing of the Dispute with the Administrator. The
      arbitrator(s) shall have the authority to impose sanctions on any party
      that fails to comply with time periods imposed by the Administrator or the
      arbitrator(s), including the sanction of summarily dismissing any Dispute
      or defense with prejudice. The arbitrator(s) shall have the authority to
      resolve any Dispute regarding the terms of this agreement, this
      arbitration clause, or Related Agreements, including any claim or
      controversy regarding the arbitrability of any Dispute. All limitations
      periods applicable to any Dispute or defense, whether by statute or
      agreement, shall apply to any arbitration proceeding hereunder and the
      arbitrator(s) shall have the authority to decide whether any Dispute or
      defense is barred by a limitations period and, if so, to summarily enter
      an award dismissing any Dispute or defense on that basis. The doctrines of
      compulsory counterclaim, res judicata, and collateral estoppel shall apply
      to any arbitration proceeding hereunder so that a party must state as a
      counterclaim in the arbitration proceeding any claim or controversy which
      arises out of the transaction or occurrence that is the subject matter of
      the Dispute. The arbitrator(s) may in the arbitrator(s)' discretion and at
      the request of any party: (1) consolidate in a single arbitration
      proceeding any other claim arising out of the same transaction involving
      another party to that transaction that is bound by an arbitration clause
      with Lender, such as borrowers, guarantors, sureties, and owners of
      collateral; and (2) consolidate or administer multiple arbitration claims
      or controversies as a class action in accordance with Rule 23 of the
      Federal Rules of Civil Procedure.

      (c) The arbitrator(s) shall be selected in accordance with the rules of
      the Administrator from panels maintained by the Administrator. A single
      arbitrator shall have expertise in the subject matter of the Dispute.
      Where three arbitrators conduct an arbitration proceeding, the Dispute
      shall be decided by a majority vote of the three arbitrators, at least one
      of whom must have expertise in the subject matter of the Dispute and at
      least one of whom must be a practicing attorney. The arbitrator(s) shall
      award to the prevailing party recovery of all costs and fees (including
      attorneys' fees and costs, arbitration administration fees and costs, and
      arbitrator(s)' fees). The arbitrator(s), either during the pendency of the
      arbitration proceeding or as part of the arbitration award, also may grant
      provisional or ancillary remedies including but not limited to an award of
      injunctive relief, foreclosure, sequestration, attachment, replevin,
      garnishment, or the appointment of a receiver.

      (d) Judgement upon an arbitration award may be entered in any court having
      jurisdiction, subject to the following limitation: the arbitration award
      is binding upon the parties only if the amount does not exceed Four
      Million Dollars ($4,000,000.00); if the award exceeds that limit, either
      party may demand the right to a court trial. Such a demand must be filed
      with the Administrator within thirty (30) days following the date of the
      arbitration award; if such a demand is not made with that time period, the
      amount of the arbitration award shall be binding. The computation of the
      total amount of an arbitration award shall include amounts awarded for
      attorneys' fees and costs, arbitration administration fees and costs, and
      arbitrator(s)' fees.

      (e) No provision of this arbitration clause, nor the exercise of any
      rights hereunder, shall limit the right of any party to: (1) judicially or
      non-judicially foreclose against any real or personal property collateral
      or other security; (2) exercise self-help remedies, including but not
      limited to repossession and setoff rights; or (3) obtain from a court
      having jurisdiction thereover any provisional or ancillary remedies
      including but not limited to injunctive relief, foreclosure,
      sequestration, attachment, replevin, garnishment, or the appointment of a
      receiver. Such rights can be exercised at any time, before or after
      initiation of an arbitration proceeding, except to the extent such action
      is contrary to the arbitration award. The exercise of such rights shall
      not constitute a waiver of the right to submit any Dispute to arbitration,
      and any claim or controversy related to the exercise of such rights shall
      be a Dispute to be resolved under the provisions of this arbitration
      clause. Any party may initiate arbitration with the Administrator. If any
      party desires to arbitrate a Dispute asserted against such party in a
      complaint, counterclaim, cross-claim, or third-party complaint thereto, or
      in an answer or other reply to any such pleading, such party must make an
      appropriate motion to the trial court seeking to compel arbitration, which
      motion must be filed with the court within 45 days of service of the
      pleading, or amendment thereto, setting forth such Dispute. If arbitration
      is compelled after commencement of litigation of a Dispute, the party
      obtaining an" order compelling arbitration shall commence arbitration and
      pay the Administrator's filing fees and costs within 45 days of entry of
      such order. Failure to do so shall constitute an agreement to proceed with
      litigation and waiver of the right to arbitrate. In any arbitration
      commenced by a consumer regarding a consumer Dispute, Lender shall pay one
      half of the Administrator's filing fee, up to $250.

      (f) Notwithstanding the applicability of any other law to this agreement,
      the arbitration clause, or Related Agreements between or among the
      parties, the Federal Arbitration Act, 9 U.S.C. Section 1 et seq., shall
      apply to the construction and interpretation of this arbitration clause.
      If any provision of this arbitration clause should be determined to be
      unenforceable, all other provisions of this arbitration clause shall
      remain in full force and effect.

SUCCESSOR INTERESTS. The terms of this Note shall be binding upon Borrower, and
upon Borrower's heirs, personal representatives, successors and assigns, and
shall inure to the benefit of Lender and its successors and assigns.

NOTIFY US OF INACCURATE INFORMATION WE REPORT TO CONSUMER REPORTING AGENCIES.
Please notify us if we report any inaccurate information about your account(s)
to a consumer reporting agency. Your written notice describing the specific
inaccuracy(ies) should be sent to us at the following address: Nevada State Bank
A Subsidiary of Zions Bancorporation P.O. Box 990 Las Vegas, NV 89125-0990

GENERAL PROVISIONS. Lender may delay or forgo enforcing any of its rights or
remedies under this Note without losing them. Borrower and any other person who
signs, guarantees or endorses this Note, to the extent allowed by law, waive
presentment, demand for payment, and notice of dishonor. Upon any change in the
terms of this Note, and unless otherwise expressly stated in writing, no party
who signs this Note, whether as maker, guarantor, accommodation maker or
endorser, shall be released from liability. All such parties agree that Lender
never renew or extend (repeatedly and for any length of time) this loan or
release any party or guarantor or collateral; or impair, fail to realize upon or
perfect Lender's security interest in the collateral; and take any other action
deemed necessary by Lender without the consent of or notice to anyone. All such
parties also agree that Lender may modify this loan without the consent of or
notice to anyone other than the party with whom the modification is made. The
obligations under this Note are joint and several.
<PAGE>

                                 PROMISSORY NOTE
LOAN NO: 9003                      (CONTINUED)                            PAGE 3

PRIOR TO SIGNING THIS NOTE, BORROWER READ AND UNDERSTOOD ALL THE PROVISIONS OF
THIS NOTE. BORROWER AGREES TO THE TERMS OF THE NOTE.

BORROWER ACKNOWLEDGES RECEIPT OF A COMPLETED COPY OF THIS PROMISSORY NOTE.

BORROWER:

READY MIX, INC.

BY: /s/ Clinton Levi Tryon
    --------------------------------------------------
    CLINTON LEVI TRYON, TREASURER OF READY MIX, INC.

LASER PRO Lending. Ver. 5.23.30.004 Copr. Harland Financial Solutions, Inc.
1997, 2004. All Rights Reserved. NV W.\CFI\LPL\D20.FC TR.4032 PR-RESERVED