I'm not sure about flies but mosquitoes will be a problem. Just make sure to have some good bug spray, Skin So Soft will NOT be sufficient. Have fun!
Thanks, 1stimestar, for your reply - but am still at a loss as to the insect issue. Are they worse in June as opposed to August? We have a chance to do this trip in August also - and just are not interested in having to battle the flies/mosquitos when out hiking or just birding from the car on the Denali Hwy.
In my neck of the woods there's a bug for every month. Mosquitos in June/July and then in August the blackflies come out. There isn't really a bug free month.
The mosquitos can be bad but given a choice I would pick the mosquitos over the blackflies.
As 1sttimestar mentioned, bring the bug spray.
Hope this helps,
Oh, and just to add a bit - it really varies from year to year, and also area. Where I live, there is always a breeze, so even when mosquitos are horrible elsewhere, we are usually fine. Low lying and boggy areas are usually the worst, of course. June is often the worst month for mosquitos and by August they seem to be pretty much gone. Never been bothered by flies . . . maybe regional also. June is my favorite month for the green and flowers . . . and as stated, get a good bug dope, and you'll be fine. :)
Anytime you venture out of town, you are likely to run into either mosquitoes or other flying insects but like stated above, every year is different, last year was horrid and the year before that was practically nothing. June will be better than August weather wise, but bug wise is like pulling a slot machine, who knows? The only bugless guarantee would be to stay in Anchorage or right along the coast in Seward, Valdez or Homer. But head into the forest or off the road and no guarantees.
Thanks to all who've written about the bug issue. We're forging ahead with our plans for June and will have a great time.