I'm not sure I'd taper, since that might make the season tricky. You might want to pull back slightly a day or two before the race to freshen the legs though.
My usual college summer would build up bit-by-bit ~5-7 miles a week with a 4th week a bit lower to recover.. (It looked a lot like "summer of malmo" though I only hear about that now.) I might do something like this for where you are now:
50-55-60-50 .. 55-60-65?
That leaves you at Labor Day, which I assume is the week of your race = two training cycles and some time to freshen the legs that week.
Personally, whenever I get above 60+ mpw, I add at least 2 days of doubles.
You don't mention quality workouts, which you'll want to add soon. Hill efforts, tempo, and longer intervals (e.g., 1200 or mile repeats) were always helpful summer workouts. If you give a bit more on current and goal pace, I'd be happy to give a few more ideas.