However, the running of the Hope for the Maasai Girls centre set up in 2007 has not been smooth, as angry men have often threatened its founders and some parents disowned their daughters after they went there.
"They see you as someone who is opposing their original culture, their original nature," said Pastor Jacob Momposhi Samperu, who founded the rescue centre.
Marrying off girls, who must traditionally be circumcised beforehand, provides a dowry for families. The bride price is often several cows, a prized property among the semi-nomadic Maasai.
"Marrying an uncircumcised girl degrades your value as a man. There are some rituals the girl cannot participate in if she is not circumcised," explained Martin Ololoigero, one of the managers of the rescue centre.
During school holidays, Maasai girls as young as nine undergo the dangerous mutilation meant to mark the passage from childhood to adulthood, which automatically means they can be married off, usually to older men.
"It is important for a woman to be circumcised so that she can go to her husband's home," said Olemairuj Kipaken, a Maasai elder in Narok.
"The Maasai people don't let their daughters marry unless they are circumcised unlike other tribes. When she has had it done, she becomes an adult. That is why it is good, she is in the position to go to a man's home," added Kipaken, standing cross-legged near a cattle stable.
Sitting on a bunk bed in their dormitory at the rescue centre, two teenage girls recounted how they escaped the ritual and subsequent child marriage.
"My parents died and my guardians wanted to marry me off. That's when I fled and came to this centre," said 15-year-old Mary Seela.
"Girls who are circumcised and married off lead a difficult life because some have to do menial jobs to get a small income."
Seela's fellow escapee, Sarah Setoon, also 15, agreed.
"When girls are circumcised they have a lot of difficulties during childbirth. That's why I refused to get circumcised," she said.
"They are married off to old men, and sometimes these old men may die and leave the girl facing so many problems, and she has to do odd jobs just to survive."
The Massai are not alone: many other Kenyan tribes circumcise girls as a mark of maturity from childhood.
The circumcision, also known as female genital mutilation (FGM), involves using blades -- often unsterilised and without anaesthesia -- to slice off the clitoris and sometimes other parts of the external genitalia.
Resulting medical complications or even death due to haemorrhage have stoked repugnance among many non-governmental groups and the government, leading to condemnation and even outlawing the practice.
'Gradual change' Kenyan MPs have passed legislation banning FGM, with offenders punished by a seven-year jail term or a $5 000 fine, and life imprisonment if the circumcision results in death.
Kenya's first lady Lucy Kibaki called for strict enforcement of the new law.
"These punitive penalties are deterrent enough if effectively enforced," she said early in September.
"FGM is partly responsible for the high maternal and infant mortality rates, which are very common among communities where FGM is widely practiced," Kibaki said.
But female circumcision is still widespread among the Maasai and the harmful tradition still has strong supporters.
"It is not something that will end soon. It will take time," admitted Ololoigero.
"We don't want to upset the community. Remember we come from that community. We want to have a gradual change."