We planted a rye/clover mix in our .75 acre plot this year. Both are doing exceptionally well, and the Rye is about 5-6ft tall. The seed has hardened and the stock is golden brown. I was told these are both indicators of when it's good to cut/harvest it. I'm planning to mow the rye, so turkeys can get at the seed, as well as open up the clover for some more growth. Would now be a good time, or can I wait even longer toward the start of archery season (beginning of October)?

Wait until around Labor Day and mow. The cut rye should re-seed itself and you will have another crop.