Experiment with a few options, as always. But since this is a post hoc solution, existing page structure needs to be preserved. If this were my project, I'd volunteer these two solutions:
Solution 1: No change, cheapest solution. Browsers and devices already have a back-button or some type of back function. Users will be familiar with this.
Solution 2: Back button to the right of Melen Rafting. Most users quickly realize they are in the wrong place and won't scroll to the bottom of the page or search for a back button. But if a back button is immediately present, they might use it.
This placement also won't disrupt page structure and will work well with your mobile styling.
Of course, use whatever icon or text or picture best represents your back function. I'm simply referring to its placement.
Hope it helps!