Having worked at a rock, sand and gravel plant for a couple of summers, I would have to say no way to that 590lb lift and than walking with it for 30ft. Gripping would be the main problem in holding that boulder (that's a boulder at that weight and probably has a extremely smooth surface) in the first place. In the second place you would have to get very close and very low to start the lift. Unless you have an arm reach of a starting NBA center, you could not get the hands under the center of balance. I would doubt very much if you could even roll such a boulder on that (probably) uneven ground, even if the boulder was a perfect round. Why people tell such stories on the internet still puzzles me. What do they gain?
A couple of guy's at that plant I worked at were into 55 gal oil drums lifting. Weighted around 550 full of diesel, if I remember right. They hi-pulled the to a little less than chest high by gripping the narrow rims of the barrels on each end. That was impressive raw power and finger strength. It was even harder when the barrels were half full and all the oil inside moved around, shifting the weight as you lifted. These guy's were not trained lifter's, just a couple of big, good old boy's blessed with raw strength potential.
At the old gym I trained at we had an old refrigerator in the back lot. Some of the guy's would just bear hug the thing, lift it and carry it around the fence for a few yards. That to me was very impressive. Good Luck.
