Kamelilo clan was a long time inhabitant of the current Chemelil, and they used to graze their cows in Morongyoo (napier grass), now known as Muhoroni. Nandi and Kipsigis both did business in Kesumet/Kesumo (the place for barter trade). British generals in 1905 forced Nandi out towards the highlands in order to continue their railway construction making Nandi abandon Kisumu, Chemelil, Muhoroni, Miwani, Kibigori, Kibos, Koru and Kupere that are largely inhabited by Luos today.
How did they come into Kalenjin lands?
Godfrey K. Sang tells it all in a well researched article in the Star newspaper.