Which North Dakota landmark is known for its historic dairy products?

The landmark known for its historic dairy products is the Dakota Dairy Historic Site. This site highlights the importance of dairy farming in North Dakota's agricultural history and showcases traditional dairy practices and products that have been significant to the region. The Dakota Dairy Historic Site not only preserves the history of dairy farming but also educates visitors about the evolution of dairy production and its impact on local communities.

While North Dakota State University has various programs, including those related to agriculture and dairy science, it is not specifically recognized for historic dairy products in the same way as the Dakota Dairy Historic Site. The International Scandinavian Festival focuses on cultural heritage rather than agriculture, and the Legacy of the Plains Museum covers a broad range of topics related to the region's history, which may include agriculture but does not specifically highlight dairy products. Thus, the Dakota Dairy Historic Site clearly stands out as the correct answer due to its focused emphasis on the state's dairy heritage.