COOPERATIVE AGRICULTURE 69 STRUCTURE OF THE CHALLENGE MARKETING SYSTEM Following the reorganization in 1917, the history of Challenge is one of gradual but substantial expansion This expansion has been along three general lines-number of affiliated locals, variety and quantity of products handled, and number of distributing plants. By the close of 1939 the Challenge federation embraced 37 local cooperative units, representing some 33.000 dairy- men in the States of California. Idaho, Colorado, Wyoming, Oregon, Utah, Washington, and Nevada. The names of these associations, their locations, and affiliation dates appear in table 1. The location of each plant in the Challenge system in 1939 is shown in figure 1.