In 1945–1946, the Musos Tyrelis swamp was the camp and headquarters of the Genio partisan unit, led by Lieutenant Martynas Kliausiaus-Tautvydas. The so-called Stone Island was the center of the partisans, where partisans from Gruzdžiai, Šakynos, Kruopiai, and Joniškis would gather, and where meetings of division, unit, and squad leaders would take place. Tyrelio Island was in a beautiful location, surrounded by swamps and thickets, making it difficult to access.