The rifle comes with Weaver "style" bases. Any Weaver, or Weaver type rings will fit. You should be able to put ANY scope on the rifle if you match the scope to the rings. Rings come in different heights, with scopes with a large front objective you need higher rings to make room for the scope.
In rare cases you will find some scopes will need special extension rings to work, but I cannot imagine a problem with the Ruger American.