EE001E1R
First letter: species: elk
second letter: sex: either sex
next 3 numbers GMU: unit 1
next letter/number: season: in this case: early/1st
last letter: weapon: rifle

To put it all together: elk/either sex/ unit 1/early 1stseason/rifle

EF05501R would be Elk/female/unit55/1st season/rifle
EM05501M would be elk/male/unit 55/1st/muzzleloading

Remember too that some units are grouped together, so if you decide you want to hunt unit ZZZ, and you don't find a code that has that unit in it, it is probably grouped with 1 or more other units and the tag would be good in any of those units.