The US national park service recieves a tremendous number of visitors in all kinds of situations and so their statistics are numerically meaningful. Fortunately, they publish statistics on visits. In 2016 they reported almost 1.5 billion recreactional visitor hours and this included 15 million overnight stays. Of interest here are the 2 million which were classed as backcountry overnights and another 4 million as tent campers. On average, and excluding suicides, around 120 people die each year in these parks – one every 12.5 million hours of visitation.

According to the Washington Post, who cite the National Park Service, 90% of all the deaths (2003-2007) were attrubted (in order) to the following;

1. Drowning >350
2. Vehicle Accident >250 (27% were caused by drivers distrated by the scenery)
3. Fall >150
4. Suicide >125

Wildlife attacks are amoung the rarest ways to die in the national parks. Between 2007 and 2013, 4 deaths. Much more likely causes are avalanche, pre-existing medical conditions and heat/cold exposure.
In the wild, you are venturing into their domain and as such, all wildlife should be treated with respect and caution. Statistically, however, there are much more likely ways to meet your maker.

Vehicle accidents and suicide have little specific context in backpacking and so we’ll focus on those causes more relevent to backpacking. Namely, drowning, falling, heat/cold exposure and dehydration. Each of these can be the result of a simple accident or ‘a perfect storm’, more often than not, they are caused by poor planning, in adequate equipment or lack of knowledge/experiance to judge the risk and/or apply a good technique.