Yes, a gate can be sloped. When there is cross slope where a gate needs to be, there are a few solutions. First, the ground can be excavated to make a more level area. If this is not preferred, then a sloped gate is the answer. A sloped gate can be accomplished in two ways. One solution is that the bottom of the gate is built with slope and the top remains level. A more popular choice is to rack the entire gate. When racking a gate, the vertical members remain vertical and the horizontal rails follow the slope. When hanging a sloped gate, it is almost always advisable to hinge the gate on the downhill post. The key pieces of information needed would be the distance between the posts, the amount of slope, the type and diameter of the gate posts, and the hand of the gate. The gate opening size can be measured on the level or on the slope, but it should be noted as to how this measurement was taken. The slope should be referenced as the amount of rise for the gate opening size. For example, a 12’ 7” opening, measured on the level, with a 9” rise for the 12’ 7” opening.