Yes.... no.... maybe.
Seriously, it all depends upon the size and complexity of the estate. For probably 95% of probate cases, three years would be way out of line. For probably another 4.9%, it is within reason. For the other 0.1%... well, it could take that long just to get everybody warmed up.
A real quick look at North Dakota statutues seems to indicate that three years is about the time that the court says to the personal representative, "What in tarnation is going on here? Justify yourself."