The region can be divided within Polish borders into three mezoregions: Grzeda Horodelska, Kotlina Hrubieszowska and Grzęda Sokalska. The Ukrainian part of the Highland is divided into: Pasmo Pelczansko-Mizockie, Padol Horochowski and Wyzyna Lucko-Rownienska.

Grzeda Horodelska (Horodelska Perch) is a range of flat elevations reaching 220-230 m asl. and covers the area of 190 sq km. A characteristic feature of this province is humus rich soil. This region is mostly covered by fields thanks to the fertile soil and lack of forests.

Kotlina Hrubieszowska (Hrubieszowska Valley) occupies within the Polish borders the area of 740 sq km. The valley is cut through by the valley of the Bug river and its tributary – Huczwa. The fertility of the soil in this province determined that 80 % of this province’s area is used for farming (mostly sugar-beets). There is one nature reserve located in this region. This province is also a settling ground for humans since neolithic age and therefore is rich with historical places and archeological dig sites.

Grzeda Sokalska (Sokalska Perch) is a range of elevations exceeding 300 m asl. on both sides of Bug river. The province covers the area of 720 sq km within Polish borders. The elevations consist of Cretaceous rocks covered by loess and humus soil. The region is covered mostly by fields and small forested areas. Much like Hrubieszowska Valley this region is also rich with many historical places like cemeteries, barrows and early medieval settlements.