Let it be known that calling during the day did nothing, I shot one early morning. But nothing else. I didn't get a picture because I couldn't get an angle where a dead cow isn't in the shot. And the farmer lost a heffer last night, the coyotes even went as far as to drag the fetus out.
So I had 1 moment of excitement and a day of boredom the rest of the day seeing nothing.
What did you use to as a call sound? I would not expect a food type sound, dying rabbit, etc. to be very effective. But If there hasn't been anything come in while you are there, before giving up for the day I would try a challenge howl or maybe even what sounds like coyotes fighting.
If the locals think someone new has wandered into the area, it may bring them out to see what's up and defend their territory and food supply. If you are giving up for the day, I don't think it can hurt anything really if you don't over do it.
How about the trail cam idea that was mentioned? If you don't have one and you are in the Thurston Co area, I have one you could borrow...