Retain Original Modified Date When Uploading Files to a Document Library

In SharePoint 2010 When files are uploaded to a document library the modified date gets set to the current date.  The desired behavior is to maintain the original modified date.  I am looking for suggestions on how to use VS 2010 to enforce the desired behavior.  I initially thought of an event receiver but it doesn't look like the original last modified date is exposed in the  SPItemEventReceiver class.

Any assistance is appreciated. -Mike