The male rhino was stuck in Borbeel near Haldibari beat under Kohora range of the Park since last night. The rhino could not pull itself out of the mud and died there at about 11.45 AM.
Forest officials termed the death as "natural" and removed the horn which would be kept in the custody of the forest department.
Altogether, 64 rhinos died this year in the Park with 22 due to natural causes and 23 in floods while 19 were killed by poachers.