Tourism crash in Kenya threatens their big cats
The Mara Conservancy says tourists have stayed away since the violence which followed last year's disputed election.
The group, which manages a 510 sq km area called the Mara Triangle, can no longer pay pastoralists compensation for cattle killed by lions or leopards.
This could force local people to kill the cats in order to protect livestock.
William Deed, from the Mara Conservancy, told the BBC that it was facing a shortfall of $50,000 (£25,000) per month.
The non-profit organisation relies on a percentage of park entrance fees paid by tourists.
Since it was founded in 2001, and the compensation scheme established, the number of lions in the reserve has doubled to 80.
But now the fund has been suspended, some Maasai have threatened to resume hunting the lions and leopards which kill their cows, goats and sheep.
"We have now had several close calls with locals hunting lions and leopards in return for the cattle that have been killed by these predators," said Mr Deed.
"Previously, the cattle compensation scheme we had in place would help placate such situations, however with no funding to pay for such a scheme the local communities are no longer seeing the benefits of living so closely with the wildlife."
He said the current situation was leading to strained relations with local communities.