The coordinates for this cache take you close to what has become known as "graffiti bridge". Local artist have used this place for several years to express themselves in various ways. Some are innocent messages, while some may be a little more unpleasant or even vulgar. It may be best to limit how much time young-ins spend here reading the artwork.
Your looking for a bison tube that is camouflaged for its surroundings. This should be a quick park & grab.