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Exhibit 4.13  


ESCHELON OPERATING COMPANY
  as Issuer


the
guarantors named herein 


and



THE BANK OF NEW YORK TRUST COMPANY, N.A.
  as Trustee


SUPPLEMENTAL INDENTURE


Dated
as of January 20, 2005 


83/8%
Senior Second Secured Notes due 2010 








        SUPPLEMENTAL
INDENTURE, dated as of January 20, 2005, among Eschelon Operating Company (the "Issuer"), the Initial Guarantors (as
defined herein), Advanced TelCom, Inc., a Delaware corporation ("ATI"), Shared Communications Systems, Inc., an Oregon corporation
("SCS" and, together with ATI, the "Additional Guarantors"), and The Bank of New York Trust Company,
N.A., as Trustee. 


 
 

RECITALS    
    


        WHEREAS, the Issuer, the Guarantors party thereto (the "Initial Guarantors" and, together with the Additional
Guarantors, the "Guarantors") and the Trustee have entered into an Indenture, dated as of March 17, 2004 (as amended or supplemented, the
"Indenture"), pursuant to which the Issuer has issued $165 million aggregate principal amount at maturity of 83/8% Senior Second
Secured Notes due 2010 (the "Notes") and the Initial Guarantors previously have jointly and severally guaranteed on a senior subordinated basis (the
"Initial Guarantees") certain obligations of the Issuer in respect of the Notes pursuant to the Indenture and a Notation of Guarantee executed and
delivered by them; 


        WHEREAS,
Section 9.01 of the Indenture provides that the Issuer, the Initial Guarantors and the Trustee may amend or supplement the Indenture in order to provide for the issuance
of an additional guarantee (an "Additional Guarantee" and, together with the Initial Guarantees, the
"Guarantees") pursuant to this Supplemental Indenture and an additional Notation of Guarantee (the "Additional Notation of
Guarantee") without the consent of the Holders of the Notes; 


        WHEREAS,
the Issuer, the Initial Guarantors, the Additional Guarantors and the Trustee now wish to supplement the Indenture in order to provide for the issuance of Additional Guarantees
by the Additional Guarantors as described above; 


        WHEREAS,
all acts and things prescribed by the Indenture, by law and by the charter and the bylaws (or comparable constituent documents) of the Issuer, the Initial Guarantors, the
Additional Guarantors and the Trustee have been done to make this Supplemental Indenture a valid and binding agreement of the Issuer, the Initial Guarantors, the Additional Guarantors and the Trustee,
in accordance with its terms, and to make the Additional Notations of Guarantee, when duly issued and executed by the Guarantors, a valid and binding agreement of the Guarantors: 


 
 

ARTICLE 1    
    


        SECTION
1.01.    Supplemental Indenture.    


        This
Supplemental Indenture is supplemental to the Indenture and does and shall be deemed to form a part of, and shall be construed in connection with and as part of, the
Indenture for any and all
purposes. This Supplemental Indenture shall become effective immediately upon its execution and delivery by each of the Issuer, the Guarantors and the Trustee. 


 
 

ARTICLE 2    
    


        SECTION
2.01.    Indenture.    


        From
this date, in accordance with the Indenture and by executing this Supplemental Indenture and the Additional Notation of Guarantee, the Guarantors whose signatures appear below are
subject to the relevant provisions of the Indenture relating to Guarantors to the extent provided for therein, including, without limitation, in Article 10 thereunder. 



        SECTION
2.02.    Additional Guarantee.    


        Without
limiting the generality of the foregoing, each of the Additional Guarantors hereby unconditionally, jointly and severally with each other Guarantor, guarantees to each Holder of
a Note authenticated and delivered by the Trustee and to the Trustee and its successors and assigns, that: (i) the principal of and interest and any other amounts due on the Notes will be
promptly paid in full when due, subject to any applicable grace period, whether at maturity, by acceleration or otherwise and interest on the overdue principal, if any, and interest on any interest,
to the extent lawful, on the Notes 










and
all other obligations of the Issuer to the Holders or the Trustee hereunder or thereunder will be promptly paid in full or performed, all in accordance with the terms hereof and thereof; and
(ii) in case of any extension of time of payment or renewal of any Notes or of any such other obligations, the same will be promptly paid in full when due or performed in accordance with the
terms of the extension or renewal, subject to any applicable grace period, whether at stated maturity, by acceleration or otherwise, subject, however, in the case of clauses (i) and
(ii) above, to the limitations set forth in Article Ten of the Indenture. 


 
 

ARTICLE 3    
    


        SECTION
3.01.    Notes and Guarantees.    


        Except
as specifically modified herein, the Indenture, the Notes and the Guarantees are in all respects ratified and confirmed (mutatis
mutandis) and shall remain in full force and effect in accordance with their terms with all capitalized terms used herein without definition having the same respective meanings
ascribed to them as in the Indenture. 


        SECTION
3.02.    Trustee.    


        Except
as otherwise expressly provided herein, no duties, responsibilities or liabilities are assumed, or shall be construed to be assumed, by the Trustee by reason of this Supplemental
Indenture. This Supplemental Indenture is executed and accepted by the Trustee subject to all the terms and conditions set forth in the Indenture with the same force and effect as if those terms and
conditions were repeated at length herein and made applicable to the Trustee with respect hereto. 


 
 

ARTICLE 4    
    


        SECTION
4.01.    Governing Law.    



        THIS SUPPLEMENTAL INDENTURE SHALL BE GOVERNED BY AND CONSTRUED IN ACCORDANCE WITH THE LAWS OF THE STATE OF NEW YORK.


        SECTION
4.02.    Successors.    


        All
agreements of the Issuer and the Guarantors, if any, in this Supplemental Indenture, if any, shall bind their successors. All agreements of the Trustee in this Supplemental Indenture
shall bind its successors. 


        SECTION
4.03.    Duplicate Originals.    



        All
parties may sign any number of copies of this Supplemental Indenture. Each signed copy shall be an original, but all of them together shall represent the same agreement. 


[signature page follows]







 
 

SIGNATURES    
    


        IN WITNESS WHEREOF, the parties hereto have caused this Supplemental Indenture to be duly executed, all as of the date first written above. 



	

 	
THE COMPANY
	

 	

ESCHELON OPERATING COMPANY
	

 	

By:	
 	

/s/ Geoffrey M. Boyd
 Geoffrey M. Boyd

Chief Financial Officer
	

 	
THE INITIAL GUARANTORS
	

 	

ESCHELON TELECOM, INC.

ESCHELON TELECOM OF MINNESOTA, INC.

ESCHELON TELECOM OF WASHINGTON, INC.

ESCHELON TELECOM OF COLORADO, INC.

ESCHELON TELECOM OF NEVADA, INC.

ESCHELON TELECOM OF UTAH, INC.

ESCHELON TELECOM OF OREGON, INC.

ESCHELON TELECOM OF ARIZONA, INC.

ESCHELON TELECOM OF CALIFORNIA, INC.

BUSINESS PRODUCTIVITY SOLUTIONS, INC
	

 	

By:	
 	

/s/ Geoffrey M. Boyd
 Geoffrey M. Boyd

Chief Financial Officer
	

 	
THE ADDITIONAL GUARANTORS
	

 	

ADVANCED TELCOM, INC.

SHARED COMMUNICATIONS SYSTEMS, INC.
	

 	

By:	
 	

/s/ Geoffrey M. Boyd
 Geoffrey M. Boyd

Chief Financial Officer
	

 	
TRUSTEE
	

 	

THE BANK OF NEW YORK TRUST COMPANY, N.A.

as Trustee
	

 	

By:	
 	

/s/ Patrick T. Giordano
 Patrick T. Giordano

Vice President













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RECITALS

ARTICLE 1

ARTICLE 2

ARTICLE 3

ARTICLE 4

SIGNATURES