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In a range of hills, or especially of mountains, a pass (also gap, notch, col, saddle, bwlch or bealach) is a lower point that allows easier access through the range. May 11, 2006 Anaheim , L 1-4. On the route through the range, it is locally the highest point on the route. Since many of the world's mountain ranges have always presented formidable barriers to travel, passes have been important since before recorded history, and have played a key role in trade, war and migration.

Topographically, a pass has the general form of a saddle between two mountains (the elevation as a function of two position coordinates is mathematically a saddle point). They are often found just above the source of a river, constituting a sort of "bridge" over to the headwaters of a different river. Passes may be very short, consisting of steep slopes to the top of the pass, or valleys of many kilometers, whose highest point is only identifiable by surveying. Goals COL J.

Roads have long been built through passes, and more recently railways. Some high and rugged passes may have tunnels bored underneath, so as allow faster traffic flow year-round.

The top of a pass is frequently the only flat ground in the area, a high vantage point, so it is often a preferred site for buildings. For countries whose borders are delimited by a mountain range, the pass is typically part of the border, and the facilities likely include a border control or customs station, and possibly a military post as well. For passes with roads, it is also customary to have a small roadside sign giving the name of the pass and its elevation above mean sea level. Specifies column-based defaults for the table properties.