The Dietz family owned a lumber yard or two here in town; I'm not sure exactly which Dietz family member is inside, since there are no inscriptions visible, but I'm going to guess it's Charles N. Dietz, the president of the company, and possibly his wife. Gould Price Dietz and his wife are buried in a regular plot right behind the mausoleum, and they might be the parents or grandparents of the Dietz clan. I have, so far, not found the graves of the rest of the bunch.
An interesting fact is that the Dietz United Methodist Church at 1423 South 10th Street in Omaha was renamed after Gould Price Dietz, evidently the richest member of the congregation. He left a considerable amount of money to the church.
Charles N. Dietz - President, C. N. Dietz Lumber Co.
Proprietor of the St. Paul's Lumber Yard, does a wholesale and retail lumber business. He located here in April, 1881, and started his yards in June of the same year. He has handled over 6,000,000 feet of lumber the past six months, and carries a stock of over 2,000,000 feet. Now he deals extensively in sash, doors, blinds and lime, and sells Omaha paints. The lime trade is very large. His trade is chiefly in Nebraska. (Bio from the 1904 Nebraskans book)
J. Frank Dietz - Vice President, C. N. Dietz Lumber Co.
Gould Dietz - Treasurer, C. N. Dietz Lumber Co.
Gould Price Dietz
The interior of the Dietz mausoleum; you can't see it in the picture, but there were a million moths flying around inside the mausoleum the day I took this. Rather a startling sight to see when you look inside a mausoleum window, expecting to see nothing moving.
Gould Price Dietz and Leonora Antoinette Dietz