Listed on National Register in 1979. Information below taken directly from Register Nomination form submitted by Terrence W. Epperson, Preservation Historian with the Idaho State University, dated 12 March 1979.
The Pocatello Hellenic Orthodox Church is a one-story structure designed in a Byzantine Revival style with a gable roof, apsidal floor plan, and red brick exterior set off by stone accents. The west (front) facade is topped by a square bell tower and round-arched gable front. The central main entrance is flanked by two round-arched, stained glass windows. Each side facade has four round-arched windows, and a doorway is located in the center of the north side facade. A cylindrical roof-tower with a conical roof and twelve small round-arched windows provides additional illumination for the nave. The church windows are done primarily in opalescent glass, with green used as the predominant color. All window designs are abstract in character and do not depict specific scenes or events. The interior space is basically one room with the main altar located in the apse end and a choir loft over the main entrance. A small secondary altar is located in the choir loft. A wooden iconostasis (altar screen) separates the sanctuary from the nave. The iconostasis is decorated with paintings of Christ, the Virgin Mary, John the Baptist, and the archangels Gabriel and Michael. Imported iconographic paintings adorn other interior walls in the church. The glass chandelier is also original and imported.
Comparison of an historic photograph (ISHI 63-211.83) with the present appearance of the building indicates that, aside from replacement of the front doors, no changes have occurred. The building is presently very well maintained and still serves as a church.
As the oldest of two Hellenic Orthodox churches in Idaho, the Pocatello structure represents several areas of architectural, historical and cultural significance. The church and its intact interior provide an excellent example of Byzantine Revival architecture and since its construction in 1915 has served as the educational, religious, and social focal point of the immigrant Greek community in Pocatello.
The Pocatello Hellenic Orthodox church was consecrated Sunday, August 15, 1915. Because of his status as one of the major donors to the church building fund, Alex Katsilometes, a Greek immigrant who came to the United States in 1907 at the age of 17, was given the honor of being church godfather. Mr. Katsilometes chose the Assumption of the Virgin Mary, which is celebrated on August 15, as the name of the new church.
Records held by the church indicate that Pocatello architect Charles B. Onderdonk was involved in the construction of the church, and may have served as project architect. Born in New York City in 1875, Onderdonk studied under McKim, Mead, and White, and came to Pocatello in 1914. The building contractor appears to have been North Pacific Construction Company. The church was constructed in the Byzantine Revival style and remains the oldest example of Greek church architecture in the state today.
Because of employment opportunities in the railroad and livestock industries, the Pocatello immigrant Greek population was the largest in the state. In 1910, 641 Greek immigrants (35% of the state total) lived in Bannock County, most in Pocatello. Historians have often cited the Church as being the primary factor which encouraged the perpetuation of Hellenic culture in the United States, and Pocatello has been no exception. Aside from its obvious religious importance, the Church of the Assumption was an important social and educational center. Even today, religious and national holidays, especially Independence Day, name days, and Easter, are celebrated at the church in the traditional style. The church also still provides instruction in Greek language and culture thus assuring the preservation of Idaho's Hellenic heritage.