I have a theory - because biology will 100% bear this out with whitetails and I suspect that elk are the same - that the rut pretty much always happens at the same time/date every year in any given location, but weather and pressure have an influence on individual animals and sometimes make small changes to the rates at which cows are successfully bred the first time, causing a variable degree of need for a second or third rut later. But most of us only see an incredibly narrow window into the 'rut' every year, whether it's elk or deer or any other ungulate. Maybe elk are pressured into being quiet, maybe they get pushed around by hunters or wolves and fewer cows get pregnant the first go-round but overall I'd be willing to bet that if you looked at spring calf drop dates and counted back the gestation period to first-round conception dates, you'd be within a day or three of the same date as previous years at any given location every time.
I could be wrong.
I'll just say that every year here in the east people will breathlessly ask each other if the rut has started yet, and it always, without fail, for all of my lifetime, always has done so at the same dates, within a day or three.