United has 19 so-called 'domestic' Boeing 777-200s, based on ch-aviation information, although not all are active. They are the non-ER versions and the original 777 variant. Few of the medium-haul aircraft were produced and even fewer remain. United's non-ER aircraft have had more seats added over the years, changing their economics and use. (It is a shame the above photo was not in the new livery, but I like it.)