Sykes spent the last few years of his life working on the railway from Clackline to Newcastle. Late in December 1890, he was found lying ill in his hut on the Clackline railway; he was removed to Newcastle Hospital, where he was diagnosed as suffering from a hepatitic ulcer and chronic hepatitis. He died five days later on 4 January 1891 and was buried in a mass grave in the Toodyay cemetery. His few belongings, including an old gun and his dog, were sold to recoup the £2/15/- that it cost the government to provide the coffin.