<PAGE>
                                                                   EXHIBIT 10.70
 
                              CONTRACT AGREEMENT

THIS AGREEMENT, made and entered into this 24th day of June, 1997, by and
between the STATE OF ARIZONA, acting by and through its State Engineer duly 
authorized by the Director, Arizona

Department of Transportation to enter into such agreement, party of the first 
part, and MEADOW VALLEY CONTRACTORS, INC. hereinafter called the Contractor, 
party of the second part.

WITNESSETH: That the said Contractor, for in consideration of the sum to be paid
him by said State Arizona in the manner and at the time hereinafter provided, 
and of the other covenants and agreements herein contained, hereby agrees, for 
himself, heirs, administrators, successors and assigns as follows:

     ARTICLE I - SCOPE OF WORK: The Contractor shall perform in a workmanlike 
and substantial manner and to the satisfaction of the State Engineer, all the 
work specified under TRACS/Project No.

101L MA 041 H406001C RAM-600-1-542
PIMA FREEWAY (101L)
(Shea Boulevard - McDonald Drive)

and furnish at his own cost and expense all necessary machinery, tools,
apparatus, materials and labor to complete the work in the most substantial and
workmanlike manner according to the Plans and Specifications therefor on file
with the State Engineer and such modifications of the same and other directions
that may be made by the State Engineer as provided herein.

     ARTICLE II - CONTRACT DOCUMENTS: It is further agreed that the Proposal, 
Plans, Standard Specifications, Special Provisions, Contract Bond(s) and any and
all Supplementary Agreements, and any and all requirements necessary to complete
the work in a substantial and acceptable manner, and any and all equipment and 
progress statements required, are hereby referred to and made a part of this 
contract, and shall have the same force and effect as though all of the same 
were fully inserted herein.

     ARTICLE III - WARRANTY: The Contractor expressly warrants that he is free 
from obligation of any other person or persons for services rendered, or 
supposed to have rendered, in the procurement of this contract. He further 
agrees that any breach of the Warranty shall constitute adequate cause for the 
annulment of the Contract by the State of Arizona and that the State of Arizona 
may retain to its own use from any sums of money due or become due thereunder, 
an amount thereof equal to any brokerage, commission, or percentage so paid, or 
agreed to be paid.

     ARTICLE IV - TIME OF COMPLETION: The Contractor further covenants and 
agrees that all of the said materials shall be furnished and delivered and all 
of the said labor shall be done and performed in every respect to the 
satisfaction and approval of the State Engineer and that the said work shall be 
turned over to the State Engineer, complete and ready for use, on or before the 
specified time herein. The work shall be free and discharged of all claims and 
demands whatsoever for, or on account of any and all labor and materials used or
furnished to be used in said work.

     It is expressly understood and agreed that in case of failure on the part 
of the Contractor, for any reason, except with the written consent of the State 
Engineer, to complete the entire work to the satisfaction of the State Engineer,
and within the aforesaid time limit, the party of the first part shall deduct 
from any money due, or which may become due the Contractor, as liquidated 
damages, an amount in accordance with Subsection 108.09 of the Contract 
Specifications.

     If no money shall be due the Contractor, the State shall have a cause of 
action to recover against the Contractor in a court of competent jurisdiction, 
liquidated damages, in accordance with Subsection 108.09 of the Contract 
Specifications, said deduction to be made, or said sum to be recovered, not as a
penalty, but as liquidated damages; provided, however, that upon receipt of 
written notice from the Contractor, of the existence of causes, as herein 
provided, over which said Contractor has no control and which must delay the 
completion of said work or any delay occasioned by the Arizona Department of 
Transportation, the State Engineer may extend the period hereinbefore specified 
for the completion of said work in accordance with the Specifications and in 
such case, the Contractor shall become liable for said liquidated damages for 
delays commencing from date said extension period shall expire.

     After the date as set up in Contract plus any extension granted, no further
payments shall be made the Contractor until all work is completed and accepted 
by the State engineer. It is also agreed that the date of completion shall be 
that upon which the work is accepted by the State Engineer. 

     ARTICLE V - CLAIMS FOR EXTRA WORK: It is distinctly understood and agreed 
that no claim for extra work or materials, not specifically herein provided, 
done or furnished by the Contractor, will be allowed by the State Engineer, nor 
shall the Contractor do any work or furnish any materials not covered by these 
Specifications and Contract, unless such work is ordered in writing by the State
Engineer. In no event shall the Contractor incur any liability by reason of any 
oral direction or instruction that he may be given by the State Engineer, or his
authorized representatives. It is the intent and meaning of this Article that 
all orders, directions, instructions, not contained in the Plans, 
Specifications, and Special Provisions, pertaining to the work shall be in 
writing, and the Contractor hereby waives any claims for compensation for work 
done, or materials furnished in violation thereof.

     ARTICLE VI - MISUNDERSTANDING OR DECEPTION: The party of the second part 
agrees that he has investigated the site of the work and all parts and 
appurtenances thereto and hereby waives any right to plead misunderstanding or 
deception as to location, character of work or materials, estimates of 
quantities or other conditions surrounding or being a part of the work and 
understands that the quantities given in the Bidding Schedule are approximate 
only, and hereby agrees to accept the quantities as actually placed and finally 
determined upon the completion of the work, in accordance with the Contract 
Documents.

     ARTICLE VII -PAYMENTS: For and in consideration of the faithful performance
of the work herein embraced, as set forth in the Contract Agreement, 
Specifications, Special Provisions, Bidding Schedule and all general and 
detailed Specifications and Plans, which are a part hereof, and in accordance 
with the directions of the State Engineer and to his satisfaction or his
authorized agents, the said State of Arizona agrees to pay to said Contractor
the amount earned, computed from the actual quantities of work performed, as
shown by the estimates of the State Engineer, and the unit prices named in the
attached Bidding Schedule and Supplementary Agreements made a part hereof, and
to make such payments in the manner and at the time provided in the
specifications hereto appended.

                                                                    Sheet 1 of 2
<PAGE>
 
     ARTICLE VIII - IT IS EXPRESSLY UNDERSTOOD AND AGREED that no work shall be 
done nor any obligations incurred under this contract during any fiscal year 
which are in excess of the funds programmed and budgeted for this project for 
that fiscal year.

     ARTICLE IX - THE CONTRACTOR SHALL INDEMNIFY AND SAVE HARMLESS THE STATE, 
its officers and employees, from all suits, actions or claims of any character
brought because of any injuries or damage received or sustained by any person,
persons or property on account of the operations of the said contractor or an
account of or in consequence of any neglect in safeguarding the work; or through
use of acceptable materials in constructing the work; or because of any act or
omission, neglect or misconduct of said contractor; or because of any claims or
amounts recovered from any infringements of patent, trademark or copyright; or
from any claims or amounts arising or recovered under the Workmen's Compensation
Act or any other law, ordinance, order or decree.

     The contractor shall indemnify and save harmless any county or incorporated
city, its officers and employees, within the limits of which county or 
incorporated city work is being performed, all in the same manner and to the 
same extent as provided in the above paragraph.

     IT IS FURTHER UNDERSTOOD AND AGREED that all work required to be done under
this contract in excess of the funds now appropriated and budgeted for this 
project shall not be done nor any obligation incurred therefor until such time
as the Legislature appropriates the additional funds and the same are budgeted 
for this project by the Arizona Department of Transportation and in that event 
the parties hereto are bound to continue performance of this contract to the 
extent permitted by the funds so appropriated and budgeted.

     In the event that no funds are appropriated or budgeted for this project
for the succeeding fiscal year, then this contract shall be null and void, 
except as to that portion for which funds have now been appropriated and 
budgeted, therefore, and no right of action or damages shall accrue to the 
benefit of the parties hereto as to that portion of the contract that may so 
become null and void.

     All parties are hereby put on notice that this contract (agreement) is 
subject to cancellation by the Governor pursuant to Arizona Revised Statutes 
Section 38-511.

     IT IS ALSO UNDERSTOOD AND AGREED that this contract is subject to A.R.S. 
28-1824, 28-1825, 28-1826, together with all other limitations pursuant to the
applicable laws of the State of Arizona relating to public contracts and
expenditures.


101L MA 041 H406001C RAM-600-1-542
PIMA FREEWAY (101L)
(Shea Boulevard - McDonald Drive)


Witness our hands and seals this 24th day of JUNE 1997

                    STATE OF ARIZONA


                                           By: [SIGNATURE ILLEGIBLE]
                                              --------------------------------
                                              for State Engineer

EVIDENCE OF AUTHORITY TO SIGN
THE CONTRACT MUST BE ON FILE
WITH THE DEPARTMENT, OTHERWISE
IT MUST BE FURNISHED WITH THE 
PROPOSAL.

                                           PARTY OF THE FIRST PART
                                           Meadow Valley Contractors, Inc.
                                           -----------------------------------

                                           By: [SIGNATURE ILLEGIBLE]
                                              --------------------------------
                                              Contractor

Attest: [SIGNATURE ILLEGIBLE]              PARTY OF THE SECOND PART
       ----------------------
              Seal

                                                                   12-0912 R8/88
                                                              Contract Agreement
                                                                    Sheet 2 of 2

ARTICLE IX
SEPT. 1969
JULY 1969
JULY 1, 1974

                   
<PAGE>
 
               STATUTORY PERFORMANCE BOND PURSUANT TO TITLE 34,
             CHAPTER 2, ARTICLE 2 OF THE ARIZONA REVISED STATUTES
          (PENALTY OF THIS BOND MUST BE 100% OF THE CONTRACT AMOUNT)

KNOW ALL MEN BY THESE PRESENTS:                        Bond No. 184239

That MEADOW VALLEY CONTRACTORS, INC. (hereinafter called the Principal), As 
Principal, and THE INSURANCE COMPANY OF THE STATE OF PENNSYLVANIA AND NATIONAL 
UNION FIRE INSURANCE COMPANY OF PITTSBURGH, PA. (hereinafter called Surety), a 
corporation organized and existing under the laws of the State of PENNSYLVANIA
with its principal office in the city of New York, New York holding a 
certificate of authority to transact surety business in Arizona issued by the 
Director of the Department of Insurance, as Surety, are held and firmly bound 
unto the Arizona Department of Transportation (hereinafter called the Obligee in
the amount of FIFTY-FOUR MILLION, SEVEN HUNDRED NINETY-EIGHT THOUSAND, FIVE 
HUNDRED EIGHTY-SEVEN AND 92/100 dollars ($54,798,587.92), for the payment 
whereof, the said Principal and Surety bind themselves, and their heirs, 
administrator, executors, successors and assigns, jointly and severally, firmly
by these presents.

    WHEREAS, the Principal has agreed to enter into a certain contract with the
Obligee for construction and completion of certain work described as 

101L MA 041 H406001C RAM-600-1-542
PIMA FREEWAY (101L)
(Shea Boulevard - McDonald Drive)

which contract is hereby referred to and made a part hereof as fully and to the 
same extent as if copied at length herein.

     NOW, THEREFORE, THE CONDITION OF THIS OBLIGATION IS SUCH, that if the said 
Principal shall faithfully perform and fulfill all the undertakings, covenants, 
terms, conditions and agreements of said contract during the original term of 
said contract any extension thereof, with or without notice to the Surety, and 
during the life of any guaranty required under the contract, and shall also 
perform and fulfill all the undertakings, covenants terms, conditions, and 
agreements of any and all duly authorized modifications of said contract that my
hereafter be made, notice of which modifications to the Surety being hereby 
waived: then the above obligation shall be void, otherwise to remain in full 
force and effect;

     PROVIDED, HOWEVER, that this bond is executed pursuant to the provisions of
Title 34, Chapter 2, Article 2, of the Arizona Revised Statues, and all 
liabilities on this bond shall be determined in accordance with the provisions 
of said Title, Chapter and Article, to the extent as if they were copied at 
length herein.

    The prevailing party in a suit on this bond shall recover as a part of the 
judgment such reasonable attorneys' fees as may be fixed by a judge of the 
Court.

    Witness our hands this 5th day of June, 1997.

MEADOW VALLEY CONTRACTORS, INC.                     /s/ Robert W. Bottcher
----------------------------------------------      ----------------------------
PRINCIPAL                      SEAL                 BY  ROBERT W. BOTTCHER
                                                           AREA MANAGER
THE INSURANCE COMPANY OF THE STATE OF
PENNSYLVANIA AND NATIONAL UNION FIRE INSURANCE
COMPANY OF PITTSBURGH, PA.                          /s/ Janina Monroe
----------------------------------------------      ----------------------------
SURETY                                              BY Janina Monroe, Attorney 
                                                        in Fact

                                                    1551 No. Tustin Avenue 
Willis Corroon Corporation                          #1000, Santa Ana, CA 92705
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AGENCY OF RECORD                                    AGENCY ADDRESS

[SIGNATURE ILLEGIBLE]
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??? COUNTERSIGNATURE

???????????????????????????????????                 PERFORMANCE BOND
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ADDRESS                                             SHEET 1 OF 1

602-870-7000
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PHONE NUMBER