Hueman Header Dimensions

I am putting a site together here:

http://oregonsbigwavecafe.com/tillamookymca/

… Using the Hueman theme. I have created my own headers in InDesign and used them in other WordPress themes with no problem, but cannot figure out why this time I cannot get the InDesign file (which I export as a pdf and then convert into a jpg) to fit the header space. I understood the header dimensions to be 1600 px wide by 240 px tall, but you can see that the result is way too small.

Does anyone have any suggestions?

Thanks!