In 1938, in Los Angeles, the Kossoner Rebbe, Rav Moshe Shmuel Rottenberg (who had previously been Rebbe in the Kloiz in Kisvarda) made a Lag B’Omer bonfire. I saw an image of the invitation to it. The invitation also referenced that he did it the previous year, so this wasn’t his first year doing it in Los Angeles.
The Kossoner moved to America in the 1930s, at which point the Salkaver Rov from Tiszaszalka, Rav Roth, took over his position in the Kloiz in Kisvarda.