Gunmen wounded Italian-born conservationist Kuki Gallmann at her conservation park in Laikipia on Sunday.
This was the latest of a string of attacks during land invasions in drought-stricken northern Kenya.
The 73-year-old author of the memoir "I Dreamed of Africa" was shot in the stomach after the vehicle she was driving in was ambushed by a group of gunmen, a family friend said.
Gallmann, who was played by Kim Basinger in the 2000 film of the book, was going to inspect fresh damage to her property after invaders burned down a retreat there on Saturday. A luxury hotel there had already been burnt down last month.
She was ambushed when she was forced to stop by a tree laid across the track, the friend said. The gunmen shot her, but Gallmann was saved when rangers from the Kenya Wildlife Service intervened and fought off the attackers.
Gallmann was first flown to a hospital in the nearby town of Nanyuki to be stabilised. British military medics accompanied her on another helicopter to receive surgery at a hospital in Kenya's capital, Nairobi, the friend said.
Her daughter -- who herself was shot at in an incident in March -- said that her mother was able to speak, the friend said.
The Gallmann family own the 100,000-acre (400 square km) Laikipia Nature Conservancy and employ 250 Kenyans on the luxury lodges, ranch, and other businesses on the land.
They also run the Gallmann Africa Conservancy and Gallmann Memorial Foundation, conservation groups focusing on bringing people and wildlife together sustainably.
A wave of violence has hit Kenya's drought-stricken Laikipia region in recent months as armed cattle-herders searching for scarce grazing land have driven tens of thousands of cattle onto private farms and ranches from poor quality communal land.
Many residents of the area accuse local politicians of inciting the violence ahead of the August elections. They say the men are trying to drive out voters who might oppose them and win votes by promising supporters access to private land.
At least 14 civilians have been killed, including local resident Duncan Murimi, who was shot in the stomach by militias and who died three days ago on a neighbouring property. Another Kenyan man was killed a few days before him in the same area.
Four police have also been killed in the last six weeks, Kenyan media has reported. Police spokesmen did not return calls seeking comment.
Martin Evans, head of the Laikipia Farmers' Association, condemned the attack on Gallmann and said "dozens of people have been killed or wounded and subjected to robbery and vandalism of their property. Kuki is a world famous author and conservationist -- but the LFA urges sympathy for all."
Raila Odinga, the country's veteran opposition leader, also condemned the attack and said "we have watched in bewilderment as hooligans take advantage of the drought to subject these ranchers to unwarranted attacks ... the government is clearly unable or unwilling to bring these attacks to a stop."
Last month, Tristan Voorspuy, a British military veteran who ran a safari company in Kenya, was shot dead at a private ranch in Laikipia.
He had gone to the ranch to inspect the remains of a friend's home that had been burnt down.