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                                                                  Exhibit (a)(1)


                  RIVERSIDE PARK ASSOCIATES LIMITED PARTNERSHIP
                     1873 South Bellaire Street, 17th Floor
                             Denver, Colorado 80222

                                  May 13, 1999

Dear Limited Partner:

         Enclosed is the Schedule 14D-9 which was filed by Riverside Park
Associates Limited Partnership (the "Partnership") with the Securities and
Exchange Commission in connection with an offer by AIMCO Properties, L.P., a
Delaware limited partnership (the "AIMCO Operating Partnership"), to purchase
units of limited partnership interest in the Partnership.

         The Partnership's general partner, Winthrop Financial Associates, is an
affiliate of the AIMCO Operating Partnership and therefore has certain conflicts
of interest in connection with the response to the offer. AS A RESULT OF THE
EXISTING AND POTENTIAL CONFLICTS OF INTEREST, THE PARTNERSHIP AND THE GENERAL
PARTNER ARE REMAINING NEUTRAL AND MAKING NO RECOMMENDATION AS TO WHETHER LIMITED
PARTNERS SHOULD TENDER THEIR UNITS IN RESPONSE TO THE OFFER. Nevertheless, the
General Partner does believe the offer is fair to the holders of units.

         Limited Partners should carefully read the enclosed Schedule 14D-9, the
Offer to Purchase of the AIMCO Operating Partnership, dated May 13, 1999
relating to the offer to acquire units of the Partnership (the "Offer to
Purchase"), and the related Letter of Transmittal and Instructions. Certain
information in the Schedule 14D-9 is incorporated by reference to the Offer to
Purchase.


                                      WINTHROP FINANCIAL ASSOCIATES          
                                      General Partner                        
                                                                             
                                      By:      /s/ Patrick J. Foye           
                                         ----------------------------------- 
                                               Executive Vice President      
                                      




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