Both in Michigan and in Illinois, my grass has tested 100% endophyte
free. My local hay farmers do not grow grass with endophyte, either.
For the curious, you get ahold of your local ag college, and they
will either send you sample containers, or you will simply break off
grass samples from all over your property, place them in a ziploc, and
mail them in (with payment). It's that simple. You get a percentage
based on the samples you took. If you think you have different grass
populations, and want to pay the fee twice, fill two ziplocs.