Below is a great photo of the map Ulleungdo Inspector Bak Seok-chang (朴錫昌) made of Ulleungdo during his inspection of the island in 1711. The map is from Mr. Tanaka Kunitaka's Web site HERE. The bottom of the map represents the east shore of Ulleungdo. The small island just off the east shore is labeled "the so-called Usando" (所謂 于山島). On the same island is also written "groves of haejang bamboo" (海長竹田).
Two kilometers off the east shore of modern-day Ulleungdo is a small island named Jukdo, which has groves of haejang bamboo on it.
Also, notice the three prominent peaks in the center of the map. Because of those three peaks, Ulleungdo was sometimes called "Sambongdo" (三峯島), which means "Island of Three Peaks."
Koreans claims that Usando was the old Korean name for Liancourt Rocks (Takeshima / Dokdo), but this 1711 Korean map is clear evidence that Usando was the old name for Ulleungdo's neighboring island of Jukdo. Liancourt Rocks are just barren rocks with no soil to grow haejang bamboo.