Marshall is a Central Yup'ik Eskimo village on the bank of the Poltes Slough, north of Arbor Island, on the east bank of the Yukon River in the Yukon-Kuskokwim Delta. It lies on the northeastern boundary of the Yukon Delta National Wildlife Refuge.

An expedition came upon an Eskimo village called "Uglovaia" at this site in 1880. Gold was discovered on nearby Wilson Creek in 1913, and a mining camp soon settled in. When a post office was established in 1915, the settlement was called "Fortuna Ledge," reportedly after a relative of postmaster Donald Hunter. Records are unclear as to whether Fortuna was the postmaster's wife, or whether she was the couple's daughter. Some say she was the first child born at the mining camp.

Later, the village came to be commonly called "Marshall's Landing," after Thomas Riley Marshall, Vice President of the United States under Woodrow Wilson from 1913-21. It was incorporated in 1970 as Fortuna Ledge, though still generally referred to as Marshall. The name was officially changed to Marshall in 1984.

Marshall never had a resident priest but Catholic missionary priests from the Society of Jesus began visiting the village soon after it was settled. Visits were infrequent at first but became more regular over the years, and in 1930 building began on the first chapel. Fifteen years later it was finally finished. It was blessed by Bishop Walter J. Fitzgerald, S.J., and dedicated to the Mother of God in 1945. A new church was built in the 1990's. It was blessed by Bishop Michael J. Kaniecki, S.J., and was dedicated to the Immaculate Heart of Mary in 1997.

Over the decades the Catholic community of Marshall has been served by priests of the Society of Jesus, or by Diocesan priests out of Saint Marys, Mountain Village, and Bethel.

Deacons have also played an important role at Immaculate Heart of Mary. Marshall has the distinction of being the first village in the Diocese of Fairbanks where, in 1975, a Native deacon was ordained.

In recent years a lay parishioner has served Immaculate Heart of Mary as a parish administrator to oversee the day to day activities of parish life. Due to priest shortages, parishes in the Yukon-Kuskokwim Delta area of the Catholic Diocese of Fairbanks are served on a rotating schedule by ministry teams which may include priests, deacons, religious and trained lay staff members. Celebrations of the Word with Holy Communion may replace Sunday Mass when a priest is unavailable. Immaculate Heart of Mary parish is presently being served by visiting ministers from Y-K Subregion C.