What would a warden be doing on YOUR land? Even if it isnt posted, most places have a law that says even if the land isnt posted you still need written permission. Wouldnt that be something like a LEO camping in your house without permission waiting for a burglar? Now, if he saw you shoot a critter on your property from a public road or area, that could be different. Still since the law varies in many parts of the nation, why not just call up your local conservation dept to find out? Many years ago I once was stopped on a old road and asked whether I was hunting or target shooting. I found out later in checking out the way the question was put, that in that area, day and age, it seemed you could hunt, but not target shoot. Go figuer! (was california, of course.)
Once many years ago I worked for the wisconsin state conservation dept. I was assigned one day to check a couple lakes for the area biologist just to see what kind of fish was being caught from a research standpoint. I walked up on 3 people that appeared to be a grandpa, son and grandson. All 3 were carrying fishing poles. They were walking towards the lake, maybe still 30 yards from the water, and me comeing up on them about 70 yards away. They froze with that deer in the headlight look, then from 70 yards away yelled at me, "we aint fishing, the boy is!" I couldnt help cracking up laughing! I just said, I aint checking licenses today, just want to see what kind of fish is being caught! I noticed they seemed to be real poor people. That was 47 years ago. I never was gung ho.
