The village of Gor Ghattas was reached on New Year's Eve in 1900 and the British and Egyptian flags were raised ‘to the tune of the Khedival March’. The party spent a year exploring the region attempting to assert government authority on the Dinka, Shulluk and Jur tribes and travelling further down the Bahr-el-Ghazal river to towns and villages as far south as the border with the Belgian Congo. Having established themselves in the province, the party was joined by further men and supplies helping to clear river routes, encourage trade and endeavouring to prevent slave trading, cattle rustling and general disputes between tribes. Sparkes Bey contracted a fever at Waw whereupon it was decided to return to Khartoum by steamer. As a reward for his role in the exploration party in Bahr-el-Ghazal, Haymes was awarded the clasp ‘Bahr-el-Ghazal 1900–1902’ for his Khedives Sudan Medal. Haymes was promoted to Captain and later in 1902 travelled to Alexandria where he ably helped control the cholera pandemic, which had claimed the lives of 35,000 people, and ‘did important sanitary medical work’. This was ‘the first attempt to fight a pandemic using modern thinking and techniques and shortly afterwards the outbreak was contained’. Haymes returned to the Sudan where he was selected by the Sirdar, Reginald Wingate (later Sir Reginald Wingate Bt GCB GCVO GBE KCMG DSO), for the appointment of Inspector of the Bahr-el-Ghazal Province. He ‘spent a year doing valuable work in surveying and boundary delimitation’ and also took up Big Game Hunting sending specimens of rarer animals back home to the British Museum. He was admitted to the Venerable Order of St John as a Serving Brother in 1901 and awarded the Order of the Medjidie (4th Class) in 1902. In February 1904, as Principal Medical Officer and Staff Officer, Haymes joined ‘a patrol of 100 men (with two Maxim machine guns) in an attempt to reopen negotiations with Chief Yambio’ and avenge the murder of a British Officer, Captain Scott-Barbour. As the patrol:  ‘approached Rikta’s village gunfire was suddenly opened up on them at a few yards range and almost simultaneously a number of spear and bowmen lying concealed in the Khor, charged the government troops.