On September 27, 1903, Fr. Vladimir Kolneff arrived to take over the parish. During 1903 and 1904, Fr. Vladimir supervised the construction of the Iconostas, and the building of the Russian School (on the site of the present Parish Hall), which in future decades became known as "The Old Saw Mill", a Globeville landmark, popular neighborhood gathering place and early social focus of the Slavic community.
Holy Transfiguration is one of the few church structures still existing in the United States that was consecrated by Bishop (now Saint) Tikhon, who was the Russian Orthodox Bishop of America from 1898 to 1907. It was St. Tikhon who accepted Holy Transfiguration parish into the Russian Orthodox Church in 1903. In 1904, St. Tikhon visited the church, and ordered the parishioners to construct an iconostas in order to conform the church to Orthodox worship in preparation of the building's consecration. Upon consecrating the church in 1905, St. Tikhon personally constructed the original altar table by hand and placed relics of his own patron saint, St. Tikhon of Zadonsk, in the original altar table. The original altar table is still contained within the present altar table, which was constructed around and above it. St. Tikhon also presented the Church with a diploma, or "Gramota", from the Holy Synod of Russia, the highest Ecclesiastical authority in the Russian Orthodox Church at that time.
In February of 1907, St. Tikhon returned to Russia, where he ruled as Bishop of Yaroslavl until 1914, when he was transferred to the Diocese of Vilnius. In 1917, St. Tikhon was elected Metropolitan of Moscow, where in 1917-1918 he presided over the All-Russia Council of the Russian Orthodox Church, which decided to restore the Russian Patriarchate, which had been suppressed in 1700 by Czar Peter the Great. On November 21, 1917, St. Tikhon was elected by his fellow Bishops to be the first Patriarch of Moscow in over 200 years. As Patriarch, St. Tikhon endured the intense persecution of the Church by the Bolsheviks, until his death on April 7, 1925.
In October of 1989, Bishop Tikhon was canonized by the Russian Orthodox Church, with the title "St. Tikhon, Enlightener of North America and Confessor of Moscow". An icon of St. Tikhon appears on the iconostas in Holy Transfiguration Church. St. Tikhon is now one of the most revered saints by the Orthodox of North America.
Several benevolent societies were connected with the church. The oldest of them is the Russian Orthodox Society Transfiguration of Christ. This society was connected with the Russian Orthodox Catholic Mutual Aid Society of Wilkes-Barre, Pa. The next oldest is the Serbian Benevolent Society "Balkan" connected with the "Serbobran" Aid Society of Pittsburgh, Pa., now the Serb National Federation.
Early pastors of Holy Transfiguration included Fr. Gregory Shutak (1905-1908), Archimandrite Sebastian Dabovich (1908-1909), Fr. Dimitri Holovitsky (1909-1913), Fr. Elias Klopotovsky (1913-1914), and Fr. Iouniky Kraskoff (1914-1916). In 1913, Mr. Stephan Kulick, a prominent parishioner, undertook a pilgrimage throughout North America to raise funds for the construction of a rectory. This was accomplished in 1914, when the old rectory on the Southwest corner of 14th and Logan Streets was sold and a large red brick rectory was constructed next to the Church.
After the departure of Fr. Iouniky in 1916, Holy Transfiguration endured a curious episode that illustrates both the difficulties of the early Orthodox Church in America and its relations with the Roman Catholic Church. A new priest, Fr. Theo Kulchinzky, arrived at the Church doorstep claiming to be sent by "the Bishop". He was welcomed, and served for a year before the Parish Council discovered that Fr. Theo was surreptiously commemorating the Roman Pope during the Divine Liturgy. Apparently, the new priest was in fact a Uniate sent by the Roman Catholic Diocese in an attempt to reclaim the Parish! When confronted by the Parish Council, Fr. Theo admitted his origins, and was told that, while the parishioners had no desire to return to Roman Catholicism, they liked him personally and would have no objections to him continuing to be Rector so long as he converted to Orthodoxy.
Fr. Theo declined this offer, and Holy Transfiguration received a new priest, Fr. Michael Kaymakan, who served from 1917 until 1922. During his tenure St. Michael the Archangel Chapel was constructed in the Orthodox section of historic Riverside Cemetery in memory of John Wysowatcky, a young parishioner who fell in combat during the First World War.