Pros
You get to work with your hands outdoors in a team and solo capacity, given the right people the team environment can be fantastic and fun. You get to engage with the public, which can be rewarding or interesting. There is always opportunity to improve the parks, and you can feel accomplished some days working at a reasonable flow.
Cons
The parks administration / upper management is remarkably out of touch with the workers in the field, and they seemingly do not care about the people who execute the work. Communication is horrendous, often leading to your day being changed quickly with no warning. Despite limitations of your day, team, or position, they will try to drive you to do more and more until you reach a point of failure and abuse your time repeatedly with no consequences. There are of course people in government that do not work hard, and there is no consequences for them. Alternatively, the reward you will receive for doing your job diligently and effectively is more work with no compensation or recognition— all while being condescended to, in the assumption that you simply are not working hard enough.