Brian Snow is a river guide on the Columbia River. Typically brian takes tourists around 30 to 80 miles upriver. Round trip takes anywhere from 2 to 8 hours before returning to dock. Brian has noted that overall fuel costs vary based on “miles upriver” and he is considering changing his guide fee to separately charge customers for estimated fuel costs. Below Brian’s log for 15 typical days showing “miles upriver” and “total fuel cost”.