What should be the path to go from an R3 to R2 or R1 school?
I'd suggest two things. First is that you don't risk not getting tenure. So, keep doing the things that your current institution values and do them well.
But to move on into a more research oriented situation, you can get yourself connected to others who do serious research and work with them as a collaborator and eventually a co-author. This can build a reputation for yourself that might be attractive to an R1 or R2 institution.
I suspect, from your &quot;handle&quot; here that you are in mathematics. Fortunately that field is easier than many others for collaboration at a distance. You can attend seminars at some nearby R1, perhaps, and introduce yourself. Conferences are another possibility. Your school library may not be adequate, but interlibrary loan will get you anything you need.
The plan may take a while to reach fruition, but it can be done.