Stanley Mission is situated on the Churchill River, close to the northern end of Lac la Ronge.
A mission station at Lac la Ronge was established in 1847 manned by native James Settee. The Rev. Robert Hunt arrived from England in 1850 and moved the station 40 miles naming it Stanley after Stanley Park, his wife's birthplace in England.
Holy Trinity Anglican Church was built 1850 to 1856, constructed by local residents. Whipsaws were used to cut lumber for the church from local logs. Windows and hardwood were brought by boat from England via Hudson Bay.
The church is now in a provincial historic park and is used by Stanley Mission residents and tourists. It is the oldest building in Saskatchewan.
Holy Trinity Church was designated a National Historic Site of Canada in 1970.