Elk will posatively THRASH trees and brush at times, but I'm not sure that its for the same purpose. I think that the wallows are the scent/terrotory markers like a rub for whitetails, dont hold me to this though.
A wallow is usually a small spring seeping out of the ground, bull elk come in and urinate all over themselves and roll in the mud, trashing the spring and making a big mud hole, covering themselves in mud. Kind of the same purpose as a deer scrape.
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Hunt as tho this year is your last in the field.
I have seen elk scrapes. They are used just like deer scrapes. They look just like a deer scrape only 3 times the size. Last year my buddies and I stumbled upon one that still was wet with urine and smelled like pure RUT. It sure got us all fired up. I'm sure it does the same thingto the elk. LOL We were on a september bowhunt, but most rifle hunters may have not seen this because the rut is over and they are not using scrapes/rubs. I have no idea about Moose.