Question about cruising RPM

I have a 1999 Jeep Wrangler TJ Sahara with 4.0 and an automatic transmission.

Cruising at 60 on the highway I am turning about 27-2800 rpm

This seems crazy high to me

Could I get some advice from the community if this is normal behavior or if I should be investigating

I only get 12-13 mpg with this vehicle.