Pros
Tons of pros. First, Yellowstone is so huge that you will live in the park. It’s a beautiful place, humble housing (unless you’re full time), some fulll time positions may be available, but they generally require work with human waste systems. If you’re previous military, you kind of have your pick of the litter when it comes to types of jobs (as long as they don’t require a specific certification). I worked in Maintenance in the SE side of the park: of course it’s beautiful. Snows in June! Snows in September! Full summer is about 2 months, but usually you get about 6 months if you haven’t worked elsewhere in the govt or have military experience. Everyone is great. Cool atmosphere. Pay is decent if you’re just getting started, but living costs tend to be low, so I had plenty of opportunity to save $ while there. If you’re outdoorsy, there’s climbing, kayaking, white water rafting, hiking, skiing (if you’re around in the winter), etc. Loved my time there. In this region and department of the park, work was 4 days on, 3 off. Oh, also, your work station will likely be right outside of your housing area, so a 1.5 minute walk.
Cons
If you’re military, I can’t tell you about cons, you are given full time status immediately if you’ve served more than 2 years. For those who aren’t military, you’ll have to work about 4 separate summer seasons (or 24 non-consecutive months) before being given the opportunity to work full-time/year-round. Unless you’re alright with doing less savory jobs. Actually, to that point, those jobs are less savory than mine, which was pressure washing outhouses within our area of the park. Same run, 2x/day i believe. It was in 2021. Still an amazing experience. In maintenance, mornings (early season) begin at 6am. Be prepared. It may still be, but definitely was a branch of the military, so it still has some of the rigor required in the military - no standing at attention or any of that, but rules are meant to be followed to the letter.