Gangs of young herders have been stirred by local politicians to invade other people’s land. Several politicians have recently been arrested. But given that official corruption is a crippling problem in Kenya, most analysts do not hold out much hope that any of the ringleaders will be seriously punished.

The Kenyan security services have deployed hundreds of officers to combat the problem, including some who are based on Mrs. Gallmann’s ranch, and recently a Humvee was parked in her front yard. Even so, herders occupy large parts of her land, making it dangerous to venture out. And the Kenyan government is increasingly distracted by national elections scheduled for August.

This past week, violence broke out across Kenya during primary balloting — a worrying sign for many Kenyans, who already dread elections because they often bring out the worst in the country, raising ethnic tensions and leading to bloodshed. Analysts say the violence between herders and landowners is worse in Laikipia this year because of the elections and because of the severe drought that has desiccated much of eastern Africa.

During several long conversations this month, Mrs. Gallmann spoke of her fears with a steely determination.

“There is absolutely no question that I want to stay in this place, die in this place, which could be any minute,” she said.

“My husband and my son are buried in my garden,” she said. “This may not mean much to an American, but it means a lot to Africans, and it means a lot to me.”

Mrs. Gallmann, who said she was a “pampered little girl” when growing up in Italy, has led both a blessed and a cursed life. Her wealth has allowed her to own one of the biggest and most beautiful ranches in Kenya, with about 100,000 acres of lush green land. But tragedy always seems to be lurking.