What if someone made a cargo carrier that articulated downward ~45° angle. You tie the deer so that it is attached to the carrier. Then on the far end on either side of the carrier there are 2 poles that swivel, and are detachable. You position these pole pointing forward and as you drive the truck forward they dig into the ground and lift the cargo carrier. You then get out of your truck, pin the cargo carrier in place, get back in your truck, back it down to allow you to remove the lift poles.

Maybe there a ~3 bars that you put in the far end of the cargo carrier vertically that when the cargo carries is at 45° angle down they are flat on the ground. These would help roll the deer onto the cargo carrier.

What are those things called that you put under a boat trailer axle and as you drive forward they will lift the trailer. Half moon like design.

They used to make one for a 4 wheeler. I forgot what they were called but a guy we hunted with in Selma had one on a kawaski bayou. It worked pretty well

Yeah, not sure if they are still being made or not. Worked okay.

Or you could do something similar to this
https://americanqualityhealthproducts.com/ramps-lifts/4569-sc500-cargo-carrier.html?msclkid=7c1e9bd0651a1ac6f09ac63adb6af51e&utm_source=bing&utm_medium=cpc&utm_campaign=Shopping%20%7C%20Variants&utm_term=4580290563855039&utm_content=GSAPI02938823874#/3227-swing_away_swings_carrier_away_from_rear_hatch-no_thanks

Small block and tackle, a tree trunk and 3 ratchet straps. It really is that simple.

There must be a hundred ways to load a deer using mostly your head instead of your back. Yet when we're young we choose to use our backs. As we age, using the ole hatrack becomes a necessity. I always keep a rope in my truck, along with an assortment of ratchet straps, bungees, etc. and even a come-a-long at times.

If you have nothing else handy, try this. Tie the rope as high as you can get it on a tree or throw it over a limb. Put your truck/side by side/ four wheeler or whatever you're going to load it on near the tree and almost facing it. Tie other end of the rope around the neck of the deer laying next to the tailgate or back end of four wheeler if you are not going to mount it. The rope should be stretched over the side of the bed. Back up a little at a time, repositioning the rope or head as needed to raise the deer into the bed or on the back rack of four wheeler.

Limb above deer, tree in front of truck or ATV, rope. Secure rope to deer and front of vehicle roughly 3 feet from the carcass, back up slowly and call it a day. They’ll be enough slack when you set it on your vehicle to untie.