This is one of a series of caches that celebrate films made by writer/director Quentin Tarantino, as well as taking the cacher to some out of the way places and experiences.
Kill Bill Volume 1 and 2 were made in 2003 and 2004, they follow the quest for revenge by The Bride (played by Tarantino regular Uma Thurman).
In case you haven't seen the movie I won't tell you if she does succed in killing Bill, but roadside memorials dotted around the country are a constant reminder of lives tragically cut short.