Do not order tires from Sam's or Walmart and expect them to mount them. They will only mount stock size tires of similar type.
I ordered 31/10.5/15 Duratracs online, waited for them to get in, took off work to have them mounted and was told that they wouldn't do it.
Manager said I could buy 215/75/15 mounted or take these somewhere else to get them mounted. I told the manager that I usually buy local and I wasn't going to do that to a local shop. If they are going to mount them, they are going to make the money off the tires.