In the intervening period, W. H. Johnson of Survey of India was commissioned to survey the Aksai Chin region. While in the course of his work, he was invited by the Khotanese ruler to visit his capital. After returning, Johnson noted that Khotan's border was at Brinjga, in the Kunlun mountains, and the entire the Karakash Valley was within the territory of Kashmir. The boundary of Kashmir that he drew, stretching from Sanju Pass to the eastern edge of Chang Chenmo Valley along the Kunlun mountains, is referred to as the Johnson Line (or Ardagh-Johnson Line).