One summer's day in 1932 Walt Disney gathered his staff in front of his animation studio complex at 2719 Hyperion Avenue in Hollywood in order to have a group photograph taken. In those early years long before Snow White and Donald Duck he already had about 100 employees, and via this 'family' photo Disney managed to have them publicly recorded for posterity*. The majority were still employed there in the summer of 1935 when Carl Barks joined the fast-growing company, and he worked with many of them. Barks started in the animation department, but was later transferred to the story department where he undertook various tasks from dreaming up ideas to directing. Due to this versatility Barks would have known all of the persons in the photograph - they were his co-workers.
This website mentions several of Barks' co-workers during his Disney years. You can see one page example HERE. Also, Barks biographer Mike Barrier has collected a series of photos depicting more of Barks' colleagues HERE.

* Several persons (or names) are missing from the photo for various reasons: 1. A person's name is uninteresting for this page if being an office clerk or in maintenance, 2. Some current staff members are not shown in the photo due to vacation days or sickness, 3. Some well-known persons from the era were not working for Disney in 1932 (examples: Ub Iwerks (left in 1930) and Jack Hannah (joined in 1933).