Most of the province was once covered with teak forests, then the major product of Uttaradit. The largest Teak tree in the world is found at the Ton Sak Yai Park in the Luang Prabang Range. The 1500 year old tree measures 9.87 m in circumference and 37 m in height - originally it was 48.5 m high, but it was damaged in a storm.