Main Beskid Trail

The Kazmierz Sosnowski Main Beskid Trail (Polish Główny Szlak Beskidzki imienia Kazmierza Sosnowskiego, "GSB") is a long-distance trail marked in red that leads from Ustroń in the Silesian Beskids to Wołosate in the Bieszczady Mountains.

At about 496 km, it is the longest trail in the Polish mountains. It crosses the Silesian Beskid, the Żywiec Beskid (Beskid Żywiecki), the Gorce Mountains, Beskid Sądecki, the Low Beskids (Beskid Niski) and the Bieszczady Mountains. Covering the highest parts of the Polish Beskids, it crosses peaks such as Stożek Wielki (Velký Stožek in Czech ), Barania Góra, Babia Góra, Polica, Turbacz, Lubań, Przehyba, Radziejowa, Jaworzyna Krynicka, Rotunda, Cergowa, Chryszczata, Smerek and Halicz as well as towns such as Ustroń, Węgierska Górka, Jordanów, Rabka-Zdrój, Krościenko nad Dunajcem, Rytro, Krynica-Zdrój, Iwonicz-Zdrój, Rymanów-Zdrój, Komańcza, Cisna and Ustrzyki Górne.

The trail was created during the interwar period. The route of the western part (Ustroń-Krynica) was designed by Kazimierz Sosnowski and it was finished in 1929. The eastern was designed by Mieczysław Orłowicz. It was completed 1935 and it led to Chornohora which, at the time, was located within the borders of Poland. Between 1935 and 1939, the trail was named after Józef Piłsudski.

Records
Many Polish ultrarunners have attempted to set new records on the trail. The current fastest known time on the trail belongs to Kamil Leśniak, who covered the trail in 93 hours, 42 minutes, and 22 seconds, beating the prior record by just under two minutes. This was a supported run, which means that the athlete could work with an external support team.