Stake outs are always unpredictable. Once we were trying to catch a group of poachers who were spotlighting and killing deer leaving the carcasses at different locations in the park. We ended up sitting right on top of a major cocaine deal. The poachers showed up the next night and killed two deer leaving them along the road shoulder for us to find.
The limited number of park rangers within most parks makes it challenging to safely mount such operations without neglecting other duties and responsibilities. A supervisor has to make a decision whether the potential danger imposed by the criminal activity warrants reducing staff during the day when the park is full of visitors. Plans are often thrown out the window when another incident takes priority. Some examples would be a missing hiker resulting in a search, a visitor injury, a fire, or as when one of my staff had not completed their online Information Technology Training and we were ordered to cancel a stake out so the required computer exercise could be completed on time. The next day we found evidence that the criminals we were attempting to apprehend had indeed been in the park.
In many instances park rangers need to coordinated resources with other agencies such as the US Forest Service or the State Game Commission so they will have enough personnel to conduct a stake out safely. These multiagency efforts were rewarding for team building purposes, but often took much more time planning, obtaining management approval, and scheduling.