The reserve was evacuated in spring, displacing hundreds of residents who have not yet been able to return to their homes.
"Families from the St. Martins reserve were hit hard from the spring flood and they've been through so much since then," said Beach in a prepared statement.
"They feel like they've been ignored by their government, they don't know if and when they'll be returning home and many of them are feeling incredible stress from daily uncertainties. This private screening will allow them to forget about their troubles, if only for one day," he said.
Below: "Hollywood actor Adam Beach in Winnipeg to help raise money for flood evacuees. Beach hosted a benefit screening of his latest movie Cowboys and Aliens in Winnipeg on Monday where $35,000 was raised."