Reports of potential presence of oil deposits in Kerio Valley have sparked land ownership rows in the area.
Some of those whose great grandparents lived in the area long ago are now claiming land ownership, expecting to reap from the oil fortunes.
British oil firm Tullow is carrying out exploration in Kerio Valley.
Cases of inter-clan violence have already been reported in the area with residents entangled in boundary disputes over land that was previously unoccupied.
Kerio Valley lies between the Tugen Hills and the Elgeyo Escarpment. It sits at an elevation of 1,000 metres in the Great Rift Valley.
A few years ago, the valley used to be a hunting and grazing ground until the reports of oil exploration.
Now those who had emigrated from the region decades ago are trooping back, only to find their previous land occupied by other people.
Two weeks ago, residents of Kamaingon sub-location in Keiyo North woke up to huge billboards erected at night announcing the arrival of the 'real' owners of the land.
"When we woke up in the morning, we were welcomed by huge billboards," said Amos Kipsat, former Keu civic leader. "We did not know who had erected them."
The billboards, which read 'Kaptoyoi clan land, Kabonon Arror', were brought down by the locals following orders from DC Moses Lilan.
Kabonon, according to Mzee Elijah Chesire, 89, were immigrants from Mount Elgon who passed the area in the early 1970s on their way to Arror, Marakwet West, where they settled.
"They just passed Kamaigon on their way to Marakwet from Baringo," said Elijah, a retired paramount chief. "They never settled here. If they want to lay claim on this land, they should also claim ownership of land in Baringo where they first settled before coming here."
He said the Kaptoyoi clan had made similar claims in 1979 a possible oil find in the area was first reported.
"We had a sitting with elders from both sides (Kamaingon and Kapyoi) but their case was dismissed by the late Paramount Chief Jonathan Sumbeiywo," he said.
Patrick Rotich from Chegilet said he belongs to the Kaptoiyoi clan after inquiries by this writer on social media. He said his grandparents had informed them that their ancestral home was Kamaingon.
He said although he was not among those who erected the billboards, the clan had made its intentions known that they are going back to their ancestral home.
"That is our home and we are not yet done," he said. "We will do everything possible to claim back our land."
Kipsat added: "They came in the middle of the night... we never saw anyone and we even don't know who they are."
On the southern side, the clan rivalry has intensified between Kapchepkok and Kapyomos clans in another boundary dispute.
The area is a long strip from the Elgeyo Escarpment to Kerio River. The Kapchepkok clan claims the boundary is marked by a borehole dug by a white settler in 1978.
Two weeks ago, members of Kapyomos clan went to construct a house at a place called Kipsoronoi which the Kapchepkok clan claim to be their ancestral land.
This heightened tension in the area after the Kapchepkok clan members brought down the structure which is said to belong to Central provincial police officer Larry Kiyeng.
Kiyeng has however denied ownership of the house despite his family members saying he is the owner. "It belongs to Larry," said Mathew Chepyego, a clan member. "It was brought down by rowdy young men from Kibendo but talks are currently going on."
"I am not involved in any dispute," Kiyeng told the Star on the phone. "I have never been to that place in my life."
Keu chief Simon Komen had earlier stopped the construction of the house until the boundary dispute was solved but the clan defied his orders.
Police were sent to hunt for the men who brought down the house but they are still at large.
The residents accuse the police officer of using his position to influence the land ownership in his favour. "Kiyeng is using his office to muscle us," said Kipsat. "He should be the one leading the search for a solution but instead he is using the local leadership to influence things in his favour."
The locals accuse the local DC and police officers of siding with the rival clan in an effort to silence them.
One of the elders who attended a meeting called by Keiyo North DC Simon Lilan said the officer is biased. However, Lilan denied the allegation, saying his office is pursuing a criminal case.
Retired chief Joseph Bartugen says the boundary dispute need to be handled carefully lest it leads to fatal scenes.
Bartugen, the retired chief of Keu location, said the DC should have talked with the elders to find a lasting solution. "Larry (Kiyeng) does not know this place... he has never stepped here and I am surprised he is claiming ownership of a land he does not know," he said.
Area OCPD John Ireri said the police will deal with any criminal activity irrespective of who commits it.
"We serve everyone... I am currently on leave but will get back to you when I go back to Iten," Ireri told the Star on the phone.
In the neighbouring locations along the valley, things are not different. Inter-clan rivalry is fuelled by speculation that there is oil in the area.
Kongot, Kayoi, Setek and other clans with a strip of land along the Kerio River, where locals believe oil is present, are claiming land ownership.
A fortnight ago, members of the Kongot clan took to the streets of Iten town, the county headquarters, protesting the illegal acquisition of their ancestral land, which they allege extends to Kerio River from the Elgeyo Escarpment, by members of a rival clan.
Waving twigs and placards, the group of old men, women and the youth said over 500 hectares have been stolen from them. The protesters wanted to seek audience with Elgeyo Marakwet Governor Alex Tolgos and other top county government officials.
"Several of our clan members are nursing serious arrow wounds and it's high time the government steps in and solves the matter as soon as possible to avert loss of lives," said 78-year-old Joseph Tunoi, a member of the Kongot clan.
He said they do not understand how the land was transferred to other people yet they are the bona fide owners of the land. "We know our boundaries by the stones which were placed by our ancestors," said Tunoi.
Most of the land in Kerio Valley is still owned communally through clans. Stones are used to mark boundaries but some residents have arbitrarily removed them and extended the borders thus fuelling the conflicts.
In addition, some natural features like gulleys and hills are also used as boundaries.
Nicholas Kiptanui, another member of the Kongot clan, said the quest to have back their land is not motivated by the oil exploration in the area. "Our fathers died while fighting to have the land back and we do not want the same fate to befall our children. The government should stick to the rules governing communal land and find a truce in this matter," said Mzee Kiptanui.
The situation could degenerate into violence if not well-handled, Elgeyo Marakwet Deputy Governor Gabriel Lamaon told the Star on phone. "We have heard reports of people claiming that they used to live in a particular place but we are not going to allow backward migration," said the deputy governor.
He urged the clans to sit down and solve the boundary disputes amicably. "We should tread on this oil issue with caution," he said. "Residents should know that minerals are owned by the government... no single person or clan will claim ownership."
Dennis Okore, community communications officer Tullow Kenya, warned the clans not to be overexcited because the process of oil exploration is at the initial stages. "The results could go either way," Okore said on the phone. "We are not even sure if the oil in Kerio Valley is commercially viable. People should not fight but instead should sit down and solve the boundary disputes peacefully."
He added that the company should not be dragged into the boundary dispute.
Rimoi Game Reserve, which is home to more than 700 elephants, faces an uncertain future should oil be struck in the area.
The reserve would be no more as it stands on Block 12, owned by Tullow Kenya.
KWS director William Kiprono, however, said they have held discussions with the company and the governors of Baringo and Elgeyo Marakwet. "We should have a migration route for our wildlife," Kiprono said. "That is an issue we raised to Tullow and the respective county governments. We are concerned of our wildlife and we have an agreement on that."
Speaking to the Star, Governor Tolgos said all land disputes in Kerio Valley will be looked into by his office.
He said elders will be the ones to determine the boundaries and urged the clans to be patient. "My office has received this information," he said on phone from his Iten office. "Land is an emotive issue and should not to be handled lightly. I want to assure you that this will be solved. We will be holding joint meetings with elders from various clans. It will be unfortunate if some try to use violence as a solution."
Tolgos urged the opinion leaders from the area to cool down their respective clans as the county government seeks solutions.