During a study on the distribution and status of the protected steppe beetle Carabus hungaricus in the vicinity of the Sofia Basin (central-western Bulgaria), 42 sample plots were surveyed in the period between May 2021 and December 2023. Via 252 pitfall traps, 69903 effective trapdays were realized, resulting in 15333 ground beetle individuals (Coleoptera: Carabidae) from 184 species, of which about 30% were characteristic of the specific steppe biota. Local faunas were studied in terms of their taxonomic, zoogeographic, size, ecological and spatial structure. The main environmental gradients, investigated by using grouping, clustering and classification methods on carabid assemblages, showed the vital relevance of the anthropogenic influence on landscapes in the context of contemporary climatic conditions and changes. Additionally, we analysed the stenotopic steppe carabids for co-occurring species and microclimatic, phytocenotic and edaphic requirements. Four stenotopic steppe carabid species were recorded (Carabus bessarabicus, C. hungaricus, Amara pastica, A. taurica), of which one subspecies (C. b. tangra) is unique to the karst steppes of the Chepan Planina and Tri Ushi Mountains. The refugium found in these two mountains represents the southernmost part of the entire Eurasian steppe biome, and is unique both in terms of its location and the complex of specific steppe species forming distinctive communities, most of which have long since disappeared from the European Union. Along with the significant carabids found in this steppe complex, some other animals of conservation importance were established—Bradyporus macrogaster, from the Orthopterans, and Common spadefoot toad (Pelobates fuscus) and Ural field mouse (Apodemus uralensis) from the vertebrates. The conservation of this biota, unique to the Bulgaria and Europe steppe, requires an urgent declaration of the two mountains as protected areas and the identified steppe species and their habitats as priorities, along with their inclusion in national and European conservation documents with strictly protected statuses.