I’m assuming that you are checking via your bookmarks, or other retained links (since you said you do not have “admin” credentials for the site)?
Was this site running some type of blog or other software (WordPress, etc?). I’m only asking that as the data for the previous content may still be in the database (if it was not altered).
Someone really needs to take a look at the site directories themselves, using FTP or a shell client, and check the DreamHost maintained “.snapshots” dirs to see if the “old” content is archived there.
The internet archive indicates that two pages were archived, though they are not available for viewing.
Obviously, the content has been deleted, moved, or renamed as you can’t see it with your existing links - the next step is to actually look at what is actually on the server.
Have you been in contact with the owners of the site to see if they will provide you with credentials to do this?
Short of doing that, suggesting that they contact DH support to see if they can retrieve an “good” backup is all I can offer in the way of help.
At any rate, the password for the FTP/Shell user should be changed immediately, and the source of the exploit should be identified - there is little point in “fixing” it only to have it hacked again.