Just returned from a week in the North Cascades National Park. Battled deer flies the entire time. Thousands of them. Everything else - the views, the weather, the friends - was perfect. Constant slathering of 99% deet (Jungle Juice) reduced the number on my body by about 75% but didn't stop them. They also died down about one hour before sun down each night. Other than netting or staying home, is there anything else you guys have successfully used on deer flies?