The Ukrainian Catholic and Ruthenian Catholic churches cover two different areas. The Ruthenian Catholic church covered a jurisdiction of Carpathia that belonged to the Kingdom of Hungary, and later the Austrian Empire and then Czechoslovakia. Today, the area that it covers is now located in Southwestern Ukraine, separate from the territories that the Ukrainian Catholic church is organized over. It was annexed to the Ukrainian Soviet Socialist Republic in the aftermath of WW2, which may seem to be the source of your geographic confusion.

The Ukrainian Catholic church is the church more identified with the Ukrainians. It was formally organized under the Polish Catholic branches which had spread into Ukraine during and after the Polish-Lithuanian takeover of Western Ukraine in the wake of the Union of Lublin. However Christianity under the Byzantine (Greek) rite had already taken shape for many years, such that when the Austrian Empire took possession of these territories they promoted the Greek rite over the Polish ones in these areas in an effort to break Polish influence and create a separate loyalty to Austria, which gave birth to the current state of the church today.