Young entered into a polygamist marriage on January 11, 1887 when he married Marion Penelope Hardy in Juarez, Mexico.

[3] As his father had hoped, Young taught in Utah's schools, first as an instructor and later as a professor of "architecture and mechanical drawing" at the University of Deseret (Salt Lake City) from 1883 to 1888; and later as a teacher of mathematics at Brigham Young Academy (Provo, Utah) from 1897 to 1900.

[4][1][5] Young's early landscape design commissions include the Utah Territorial Insane Asylum (1881, with architect John H. Burton as the asylum architect) and Salt Lake City's Liberty Park (1881–83, via a public design competition).

Young's noteworthy early architecture commissions include a dormitory for Brigham Young College (1882–1885; Logan, Utah Territory), the Bear Lake Stake Tabernacle (1883–1888; Paris, Idaho), the Brigham Young Academy (designed in 1884, completed 1892; Provo, Utah Territory) and the Templeton (Zion's Bank) Building (designed in 1883, completed 1890; Salt Lake City).

After re-designing the towers and finials, and the final appearance of the windows, Young focused his energies on designing the temple's lavish late Victorian/Neo-baroque interior.

At mid-career Young practiced with his oldest son, Don Carlos Young, as Young & Son, Architects; and was responsible for the design of the 2nd Eagle Gate (c. 1892, an overarching symbolic gateway to Brigham Young's Salt Lake farm), Latter-day Saint University (later LDS College and LDS Business College, located on the corner of North Temple and Main Street); the LDS Church's Bishop's Building (50 North Main St.), and the Church Administration Building (47 East South Temple).

[8] D. C. Young Jr., was also responsible for designing with Danish emigrant Ramm Hansen (as Young & Hansen, architects) the LDS Church's flagship meetinghouse in Washington, D.C., known as the "Washington Chapel," located on 2810 Sixteenth Street, N.W., sheathed no less in railroad shipped Utah granite.

With his son, Richard Young, G. C. Young designed the LDS Church's twenty-eight story Church Office Building (completed 1972; Salt Lake City) which was the tallest building in Salt Lake City until 1998.