 Rather than comply , Detzner led his party , on a forced march north to the Markham Valley . His route is uncertain , but his description of a valley with steep grassy ravines entering from east and west may place the latter part of his journey in the Langimar Valley , through which flows a tributary of the Watut River . A clash with local people that he describes has been identified as having occurred at Rangama among with Middle Watut people . Once on the Watut itself , the party built rafts and floated downstream to the Markham . 
