<PAGE>
 
                                                                      EXHIBIT 24

                               POWER OF ATTORNEY


     KNOW ALL MEN BY THESE PRESENTS, that the undersigned hereby constitutes and
appoints R. A. Tinstman, S. G. Hanks and A. S. Cleberg, and each of them, his
true and lawful attorneys-in-fact and agents, with full power of substitution
and resubstitution, for him and in his name, place and stead, in any and all
capacities, to sign on his behalf as a director or officer or both, as the case
may be, of Morrison Knudsen Corporation, a Delaware corporation, Form 10-K
Annual Report for fiscal year ended November 30, 1997, and any and all
amendments thereto, and to file the same, with all exhibits thereto, and other
documents in connection therewith, with the Securities and Exchange Commission,
granting unto said attorneys-in-fact and agents, and each of them, full power
and authority to do and perform each and every act and thing requisite and
necessary to be done in and about the premises, as fully to all intents and
purposes as each of them might or could do in person, hereby ratifying and
confirming all that said attorneys-in-fact and agents, or any of them, or their
substitute or substitutes, may lawfully do or cause to be done by virtue hereof.

     Pursuant to the requirements of the Securities Exchange Act of 1934, this
Power of Attorney has been signed below on the  15  day of January, 1998.
                                               ----                      


                              /s/ Dennis R. Washington
                              ______________________________________
                              Dennis R. Washington, Chairman
<PAGE>
 
                               POWER OF ATTORNEY


     KNOW ALL MEN BY THESE PRESENTS, that the undersigned hereby constitutes and
appoints R. A. Tinstman, S. G. Hanks and A. S. Cleberg, and each of them, his
true and lawful attorneys-in-fact and agents, with full power of substitution
and resubstitution, for him and in his name, place and stead, in any and all
capacities, to sign on his behalf as a director or officer or both, as the case
may be, of Morrison Knudsen Corporation, a Delaware corporation, Form 10-K
Annual Report for fiscal year ended November 30, 1997, and any and all
amendments thereto, and to file the same, with all exhibits thereto, and other
documents in connection therewith, with the Securities and Exchange Commission,
granting unto said attorneys-in-fact and agents, and each of them, full power
and authority to do and perform each and every act and thing requisite and
necessary to be done in and about the premises, as fully to all intents and
purposes as each of them might or could do in person, hereby ratifying and
confirming all that said attorneys-in-fact and agents, or any of them, or their
substitute or substitutes, may lawfully do or cause to be done by virtue hereof.

     Pursuant to the requirements of the Securities Exchange Act of 1934, this
Power of Attorney has been signed below on the  15   day of January, 1998.
                                               -----                      

                              /s/ David H. Batchelder
                              ______________________________________
                              David H. Batchelder
                              Director
<PAGE>
 
                               POWER OF ATTORNEY


     KNOW ALL MEN BY THESE PRESENTS, that the undersigned hereby constitutes and
appoints R. A. Tinstman, S. G. Hanks and A. S. Cleberg, and each of them, his
true and lawful attorneys-in-fact and agents, with full power of substitution
and resubstitution, for him and in his name, place and stead, in any and all
capacities, to sign on his behalf as a director or officer or both, as the case
may be, of Morrison Knudsen Corporation, a Delaware corporation, Form 10-K
Annual Report for fiscal year ended November 30, 1997, and any and all
amendments thereto, and to file the same, with all exhibits thereto, and other
documents in connection therewith, with the Securities and Exchange Commission,
granting unto said attorneys-in-fact and agents, and each of them, full power
and authority to do and perform each and every act and thing requisite and
necessary to be done in and about the premises, as fully to all intents and
purposes as each of them might or could do in person, hereby ratifying and
confirming all that said attorneys-in-fact and agents, or any of them, or their
substitute or substitutes, may lawfully do or cause to be done by virtue hereof.

     Pursuant to the requirements of the Securities Exchange Act of 1934, this
Power of Attorney has been signed below on the   15  day of January, 1998.
                                                ----                      


                              /s/ Leonard R. Judd
                              ______________________________________
                              Leonard R. Judd
                              Director
<PAGE>
 
                               POWER OF ATTORNEY


     KNOW ALL MEN BY THESE PRESENTS, that the undersigned hereby constitutes and
appoints R. A. Tinstman, S. G. Hanks and A. S. Cleberg, and each of them, his
true and lawful attorneys-in-fact and agents, with full power of substitution
and resubstitution, for him and in his name, place and stead, in any and all
capacities, to sign on his behalf as a director or officer or both, as the case
may be, of Morrison Knudsen Corporation, a Delaware corporation, Form 10-K
Annual Report for fiscal year ended November 30, 1997, and any and all
amendments thereto, and to file the same, with all exhibits thereto, and other
documents in connection therewith, with the Securities and Exchange Commission,
granting unto said attorneys-in-fact and agents, and each of them, full power
and authority to do and perform each and every act and thing requisite and
necessary to be done in and about the premises, as fully to all intents and
purposes as each of them might or could do in person, hereby ratifying and
confirming all that said attorneys-in-fact and agents, or any of them, or their
substitute or substitutes, may lawfully do or cause to be done by virtue hereof.

     Pursuant to the requirements of the Securities Exchange Act of 1934, this
Power of Attorney has been signed below on the  13  day of January, 1998.
                                               ----                      


                              /s/ William C. Langley
                              ______________________________________
                              William C. Langley
                              Director
<PAGE>
 
                               POWER OF ATTORNEY


     KNOW ALL MEN BY THESE PRESENTS, that the undersigned hereby constitutes and
appoints R. A. Tinstman, S. G. Hanks and A. S. Cleberg, and each of them, his
true and lawful attorneys-in-fact and agents, with full power of substitution
and resubstitution, for him and in his name, place and stead, in any and all
capacities, to sign on his behalf as a director or officer or both, as the case
may be, of Morrison Knudsen Corporation, a Delaware corporation, Form 10-K
Annual Report for fiscal year ended November 30, 1997, and any and all
amendments thereto, and to file the same, with all exhibits thereto, and other
documents in connection therewith, with the Securities and Exchange Commission,
granting unto said attorneys-in-fact and agents, and each of them, full power
and authority to do and perform each and every act and thing requisite and
necessary to be done in and about the premises, as fully to all intents and
purposes as each of them might or could do in person, hereby ratifying and
confirming all that said attorneys-in-fact and agents, or any of them, or their
substitute or substitutes, may lawfully do or cause to be done by virtue hereof.

     Pursuant to the requirements of the Securities Exchange Act of 1934, this
Power of Attorney has been signed below on the  15   day of January, 1998.
                                               -----                      


                                    /s/ Robert S. Miller, Jr.
                                    ______________________________________
                                    Robert S. Miller, Jr.
                                    Director
<PAGE>
 
                               POWER OF ATTORNEY


     KNOW ALL MEN BY THESE PRESENTS, that the undersigned hereby constitutes and
appoints R. A. Tinstman, S. G. Hanks and A. S. Cleberg, and each of them, his
true and lawful attorneys-in-fact and agents, with full power of substitution
and resubstitution, for him and in his name, place and stead, in any and all
capacities, to sign on his behalf as a director or officer or both, as the case
may be, of Morrison Knudsen Corporation, a Delaware corporation, Form 10-K
Annual Report for fiscal year ended November 30, 1997, and any and all
amendments thereto, and to file the same, with all exhibits thereto, and other
documents in connection therewith, with the Securities and Exchange Commission,
granting unto said attorneys-in-fact and agents, and each of them, full power
and authority to do and perform each and every act and thing requisite and
necessary to be done in and about the premises, as fully to all intents and
purposes as each of them might or could do in person, hereby ratifying and
confirming all that said attorneys-in-fact and agents, or any of them, or their
substitute or substitutes, may lawfully do or cause to be done by virtue hereof.

     Pursuant to the requirements of the Securities Exchange Act of 1934, this
Power of Attorney has been signed below on the  15  day of January, 1998.
                                               ----                      


                              /s/ Dorn Parkinson
                              ______________________________________
                              Dorn Parkinson
                              Director
<PAGE>
 
                               POWER OF ATTORNEY


     KNOW ALL MEN BY THESE PRESENTS, that the undersigned hereby constitutes and
appoints R. A. Tinstman, S. G. Hanks and A. S. Cleberg, and each of them, his
true and lawful attorneys-in-fact and agents, with full power of substitution
and resubstitution, for him and in his name, place and stead, in any and all
capacities, to sign on his behalf as a director or officer or both, as the case
may be, of Morrison Knudsen Corporation, a Delaware corporation, Form 10-K
Annual Report for fiscal year ended November 30, 1997, and any and all
amendments thereto, and to file the same, with all exhibits thereto, and other
documents in connection therewith, with the Securities and Exchange Commission,
granting unto said attorneys-in-fact and agents, and each of them, full power
and authority to do and perform each and every act and thing requisite and
necessary to be done in and about the premises, as fully to all intents and
purposes as each of them might or could do in person, hereby ratifying and
confirming all that said attorneys-in-fact and agents, or any of them, or their
substitute or substitutes, may lawfully do or cause to be done by virtue hereof.

     Pursuant to the requirements of the Securities Exchange Act of 1934, this
Power of Attorney has been signed below on the  15   day of January, 1998.
                                               -----                      


                              /s/ Terry W. Payne
                              ______________________________________
                              Terry W. Payne
                              Director
<PAGE>
 
                               POWER OF ATTORNEY


     KNOW ALL MEN BY THESE PRESENTS, that the undersigned hereby constitutes and
appoints R. A. Tinstman, S. G. Hanks and A. S. Cleberg, and each of them, his
true and lawful attorneys-in-fact and agents, with full power of substitution
and resubstitution, for him and in his name, place and stead, in any and all
capacities, to sign on his behalf as a director or officer or both, as the case
may be, of Morrison Knudsen Corporation, a Delaware corporation, Form 10-K
Annual Report for fiscal year ended November 30, 1997, and any and all
amendments thereto, and to file the same, with all exhibits thereto, and other
documents in connection therewith, with the Securities and Exchange Commission,
granting unto said attorneys-in-fact and agents, and each of them, full power
and authority to do and perform each and every act and thing requisite and
necessary to be done in and about the premises, as fully to all intents and
purposes as each of them might or could do in person, hereby ratifying and
confirming all that said attorneys-in-fact and agents, or any of them, or their
substitute or substitutes, may lawfully do or cause to be done by virtue hereof.

     Pursuant to the requirements of the Securities Exchange Act of 1934, this
Power of Attorney has been signed below on the  14  day of January, 1998.
                                               ----                      


                              /s/ John D. Roach
                              ______________________________________
                              John D. Roach
                              Director