I just got back from the fort yesterday, and here's what I used to deter these bloodsucking flies

After reading all over the internet to find a possible fix for this problem, I came up with a trap that worked pretty good. Similar to the device found at the link from the OP, before I left home, I took 2 beach balls and spray painted them the brightest blue I could find (not black like shown in the article). When I got to the site I hung them from strings tied to the trees. (put in a shaded area about 20ft away from where you'd like to sit). Because I can't buy TangleTrap anywhere local, I coated the balls with mixture of resin and sugar. Each day I'd just pour a fresh coat of resin over the balls to keep them sticky. Over 3 days, I trapped about 30 of these suckers, and came home with only 1 bite from the trip. Not perfect but it sure helped!