Wamu Mor Pass Thru Cert Ser 2001-Ar1 Sample Contracts

Wamu Mor Pass Thru Cert Ser 2001-Ar1 – WASHINGTON MUTUAL MORTGAGE SECURITIES CORP. (June 23rd, 2004)

EXHIBIT 99 WASHINGTON MUTUAL MORTGAGE SECURITIES CORP. MASTER SERVICING MORTGAGE PASS-THROUGH CERTIFICATES 04/2003 DISTRIBUTION REPORT SERIES: wamu 2001-ar1 WEIGHTED AVERAGE PC RATE: 6.12050% POOL NUMBER: Group 1 = 1762, 1763 ____________________________________________________________________________________________ ISSUE DATE: 08/24/2001 CERTIFICATE BALANCE AT ISSUE: $741,185,905.00 CERTIFICATE TOTAL ACCOUNT CERTIFICATE NUMBER OF ACTIVITY BALANCE MORTGAGES (@PC RATE) OUTSTANDING

Wamu Mor Pass Thru Cert Ser 2001-Ar1 – WASHINGTON MUTUAL MORTGAGE SECURITIES CORP. (June 23rd, 2004)

EXHIBIT 99 WASHINGTON MUTUAL MORTGAGE SECURITIES CORP. MASTER SERVICING MORTGAGE PASS-THROUGH CERTIFICATES 02/2003 DISTRIBUTION REPORT SERIES: wamu 2001-ar1 WEIGHTED AVERAGE PC RATE: 6.12952% POOL NUMBER: Group 1 = 1762, 1763 ____________________________________________________________________________________________ ISSUE DATE: 08/24/2001 CERTIFICATE BALANCE AT ISSUE: $741,185,905.00 CERTIFICATE TOTAL ACCOUNT CERTIFICATE NUMBER OF ACTIVITY BALANCE MORTGAGES (@PC RATE) OUTSTANDING

Wamu Mor Pass Thru Cert Ser 2001-Ar1 – WASHINGTON MUTUAL MORTGAGE SECURITIES CORP. (June 23rd, 2004)

EXHIBIT 99 WASHINGTON MUTUAL MORTGAGE SECURITIES CORP. MASTER SERVICING MORTGAGE PASS-THROUGH CERTIFICATES 03/2003 DISTRIBUTION REPORT SERIES: wamu 2001-ar1 WEIGHTED AVERAGE PC RATE: 6.12981% POOL NUMBER: Group 1 = 1762, 1763 ____________________________________________________________________________________________ ISSUE DATE: 08/24/2001 CERTIFICATE BALANCE AT ISSUE: $741,185,905.00 CERTIFICATE TOTAL ACCOUNT CERTIFICATE NUMBER OF ACTIVITY BALANCE MORTGAGES (@PC RATE) OUTSTANDING

Wamu Mor Pass Thru Cert Ser 2001-Ar1 – WASHINGTON MUTUAL MORTGAGE SECURITIES CORP. (June 23rd, 2004)

The Class Principal Balances of each Class of the Class B1,B2,B3,B4,B5,B6 Certificatesimmediately after the principal and interest distribution on 200301 are as follows:

Wamu Mor Pass Thru Cert Ser 2001-Ar1 – WASHINGTON MUTUAL MORTGAGE SECURITIES CORP. (February 4th, 2004)

The Class Principal Balances of each Class of the Class B1,B2,B3,B4,B5,B6 Certificatesimmediately after the principal and interest distribution on 200401 are as follows:

Wamu Mor Pass Thru Cert Ser 2001-Ar1 – WASHINGTON MUTUAL MORTGAGE SECURITIES CORP. (January 7th, 2004)

The Class Principal Balances of each Class of the Class B1,B2,B3,B4,B5,B6 Certificatesimmediately after the principal and interest distribution on 200312 are as follows:

Wamu Mor Pass Thru Cert Ser 2001-Ar1 – WASHINGTON MUTUAL MORTGAGE SECURITIES CORP. (December 4th, 2003)

The Class Principal Balances of each Class of the Class B1,B2,B3,B4,B5,B6 Certificatesimmediately after the principal and interest distribution on 200311 are as follows:

Wamu Mor Pass Thru Cert Ser 2001-Ar1 – WASHINGTON MUTUAL MORTGAGE SECURITIES CORP. (November 4th, 2003)

The Class Principal Balances of each Class of the Class B1,B2,B3,B4,B5,B6 Certificatesimmediately after the principal and interest distribution on 200310 are as follows:

Wamu Mor Pass Thru Cert Ser 2001-Ar1 – WASHINGTON MUTUAL MORTGAGE SECURITIES CORP. (October 9th, 2003)

The Class Principal Balances of each Class of the Class B1,B2,B3,B4,B5,B6 Certificatesimmediately after the principal and interest distribution on 200309 are as follows:

Wamu Mor Pass Thru Cert Ser 2001-Ar1 – WASHINGTON MUTUAL MORTGAGE SECURITIES CORP. (September 5th, 2003)

The Class Principal Balances of each Class of the Class B1,B2,B3,B4,B5,B6 Certificatesimmediately after the principal and interest distribution on 200308 are as follows:

Wamu Mor Pass Thru Cert Ser 2001-Ar1 – WASHINGTON MUTUAL MORTGAGE SECURITIES CORP. (August 8th, 2003)

EXHIBIT 99 WASHINGTON MUTUAL MORTGAGE SECURITIES CORP. MASTER SERVICING MORTGAGE PASS-THROUGH CERTIFICATES 07/2003 DISTRIBUTION REPORT SERIES: wamu 2001-ar1 WEIGHTED AVERAGE PC RATE: 6.12720% POOL NUMBER: Group 1 = 1762, 1763 ____________________________________________________________________________________________ ISSUE DATE: 08/24/2001 CERTIFICATE BALANCE AT ISSUE: $741,185,905.00 CERTIFICATE TOTAL ACCOUNT CERTIFICATE NUMBER OF ACTIVITY BALANCE MORTGAGES (@PC RATE) OUTSTANDING

Wamu Mor Pass Thru Cert Ser 2001-Ar1 – WASHINGTON MUTUAL MORTGAGE SECURITIES CORP. (July 8th, 2003)

EXHIBIT 99 WASHINGTON MUTUAL MORTGAGE SECURITIES CORP. MASTER SERVICING MORTGAGE PASS-THROUGH CERTIFICATES 06/2003 DISTRIBUTION REPORT SERIES: wamu 2001-ar1 WEIGHTED AVERAGE PC RATE: 6.12454% POOL NUMBER: Group 1 = 1762, 1763 ____________________________________________________________________________________________ ISSUE DATE: 08/24/2001 CERTIFICATE BALANCE AT ISSUE: $741,185,905.00 CERTIFICATE TOTAL ACCOUNT CERTIFICATE NUMBER OF ACTIVITY BALANCE MORTGAGES (@PC RATE) OUTSTANDING

Wamu Mor Pass Thru Cert Ser 2001-Ar1 – WASHINGTON MUTUAL MORTGAGE SECURITIES CORP. (June 10th, 2003)

EXHIBIT 99 WASHINGTON MUTUAL MORTGAGE SECURITIES CORP. MASTER SERVICING MORTGAGE PASS-THROUGH CERTIFICATES 05/2003 DISTRIBUTION REPORT SERIES: wamu 2001-ar1 WEIGHTED AVERAGE PC RATE: 6.12649% POOL NUMBER: Group 1 = 1762, 1763 ____________________________________________________________________________________________ ISSUE DATE: 08/24/2001 CERTIFICATE BALANCE AT ISSUE: $741,185,905.00 CERTIFICATE TOTAL ACCOUNT CERTIFICATE NUMBER OF ACTIVITY BALANCE MORTGAGES (@PC RATE) OUTSTANDING

Wamu Mor Pass Thru Cert Ser 2001-Ar1 – WASHINGTON MUTUAL MORTGAGE SECURITIES CORP. (January 10th, 2002)

EXHIBIT 99 WASHINGTON MUTUAL MORTGAGE SECURITIES CORP. MASTER SERVICING MORTGAGE PASS-THROUGH CERTIFICATES 12/2001 DISTRIBUTION REPORT SERIES: wamu 2001-ar1 WEIGHTED AVERAGE PC RATE: 6.17527% POOL NUMBER: Group 1 = 1762, 1763 ____________________________________________________________________________________________ ISSUE DATE: 08/24/2001 CERTIFICATE BALANCE AT ISSUE: $741,185,905.00 CERTIFICATE TOTAL ACCOUNT CERTIFICATE NUMBER OF ACTIVITY BALANCE MORTGAGES (@PC RATE) OUTSTANDING

Wamu Mor Pass Thru Cert Ser 2001-Ar1 – WASHINGTON MUTUAL MORTGAGE SECURITIES CORP. (December 5th, 2001)

EXHIBIT 99 WASHINGTON MUTUAL MORTGAGE SECURITIES CORP. MASTER SERVICING MORTGAGE PASS-THROUGH CERTIFICATES 11/2001 DISTRIBUTION REPORT SERIES: wamu 2001-ar1 WEIGHTED AVERAGE PC RATE: 6.17747% POOL NUMBER: Group 1 = 1762, 1763 ____________________________________________________________________________________________ ISSUE DATE: 08/24/2001 CERTIFICATE BALANCE AT ISSUE: $741,185,905.00 CERTIFICATE TOTAL ACCOUNT CERTIFICATE NUMBER OF ACTIVITY BALANCE MORTGAGES (@PC RATE) OUTSTANDING

Wamu Mor Pass Thru Cert Ser 2001-Ar1 – SECURITIES AND EXCHANGE COMMISSION 450 Fifth Street, NW Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 For the Month of September, 2001 WASHINGTON MUTUAL MORTGAGE SECURITIES CORP. MORTGAGE PASS-THROUGH CERTIFICATES, SERIES 2001-AR1 (Exact name of the registrant as specified in charter) Delaware 333-67140-01 94-2528990 (State or other (Commission (IRS Employer jurisdiction of File Number) Identification Incorporation) Number) (October 10th, 2001)

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

Wamu Mor Pass Thru Cert Ser 2001-Ar1 – POOLING AND SERVICING AGREEMENT (September 6th, 2001)

EXECUTION VERSION WASHINGTON MUTUAL MORTGAGE SECURITIES CORP., as Depositor and Master Servicer and STATE STREET BANK AND TRUST COMPANY, as Trustee POOLING AND SERVICING AGREEMENT $741,185,906.39 Washington Mutual Mortgage Securities Corp. WaMu Mortgage Pass-Through Certificates Series 2001-AR1 Cut-Off Date: August 1, 2001 TABLE OF CONTENTS Page ----