Bohlen, Meyer, Gibson and Associates, or BMG, is an architectural firm based in Indianapolis, Indiana.

[2] The designs for several of his buildings, including the Indianapolis City Market façade (1886), exhibit the Romanesque Revival architecture style called Rundbogenstil.

August Carl Bohlen, Oscar's son, joined the firm in 1910, and later co-authored Indiana's original building codes.

Following D. A. Bohlen's death on June 1, 1890, Oscar continued the family firm on his own until 1910, except for the period between 1897 and 1899, when Hugo Zigrosser was his partner.

[1][16] The firm specialized in institutional structures for religious, educational, and civic institutions, although it did design some private residences for well-do-to families, such as the French mansard-style Morris-Butler House (1864) in Indianapolis and the Neo-Jacobean-style Churchman House (1871) on a farm that later became part of Beech Grove, Indiana.

[16][20] In 1891 Bohlen's firm submitted a design for a proposed Indiana building to be erected at the World's Columbian Exposition (1893) at Chicago.

The selection committee narrowed its choice to two plans, one from the Bohlen firm and the other from Wing and Mahurin of Fort Wayne, Indiana.

In a controversial move from the committee's leadership, a design proposed by Chicago architect Henry Ives Cobb was recommended to the Indiana Board of World's Fair Managers and built for the exposition, despite protests from the Indiana architects who argued that Cobb's plan arrived after the contest deadline.

[1] Providence motherhouse and chapel (1853–4, 1863), Foley Hall (1860), and the Church of the Immaculate Conception (1892) are among Diedrich Bohlen's early renovations and designs for the Sisters of Providence on the grounds of Saint Mary-of-the-Woods College, a Roman Catholic liberal arts college near Terre Haute, Indiana.

After D. A. Bohlen's death in 1890, Oscar continued his father's legacy as community architect at Saint Mary-of-the-Woods.

The church's interior decoration was completed in 1907, and it underwent a major renovation in 1987, with Melvin Meyer as the project architect.

[32][33][34] D. A. Bohlen also designed Saint John the Evangelist Catholic Church (1871), the main structure in a cluster of parish buildings on the southwest corner of Georgia Street and Capitol Avenue in Indianapolis that includes a D. A. Bohlen-designed rectory (1863) and bishop's residence (1878).

D. A. Bohlen's son, Oscar, designed the twin spires on the two towers that flank the church's main façade and supervised their construction in 1893.

[39] Numerous commercial and several notable civic structures were designed in Indianapolis during Oscar Bohlen's tenure at the firm.

Oscar Bohlen's most notable commercial structure was the Majestic Building (1896), a commission from the Indiana Gas Company, at 47 South Pennsylvania Street.

[40] Oscar also designed the Indiana National Bank building (1897), a Neoclassical structure at Three Virginia Avenue.

The firm's other major projects in Indianapolis during the early twentieth century included the Oscar Bohlen-designed Murat Temple (1910) at Massachusetts Avenue and New Jersey and Michigan Streets.

Oscar Bohlen designed the hospital's second building (1889) on South and Delaware Streets, and after it was destroyed by fire in 1904, the Bohlen firm designed the third Saint Vincent Hospital (1913) building facing Fall Creek Parkway, between Capitol and Illinois Streets.