When hunting from an elevated stand or ground blind, you can pace off the distance to permanent markers, such as stumps and trees, to get an accurate measure to spots that offer potential shots.
A range finder is an accurate distance measuring tool used by many hunters. The devices vary in design and cost. Generally, the better the quality, the greater the accuracy when used correctly. However, most crossbow hunters predetermine distances in an area where they anticipate spotting game, which allows them to concentrate on taking a shot when game arrives, rather than making calculations. Usually there isn’t enough time to range an animal when it appears, and most crossbow hunters choose to avoid extra movement in the presence of game. Range finders are highly recommended when hunting in mountainous or tundra-type terrain since judging distances can be very difficult.