>> One of the most important things an agent learns to do
in the Border Patrol is to track and ###make signs.
On the Southern border, dirt's there all the time.
They cross over the border, you track it.
And there's ways to tell the age of it.
On the Northern border, the terrain is different.
There's, you know, there's trees, there's leaves on the ground,
all sorts of different effects, stuff that affects how signs left.
When the snow falls, it makes it easier for us
because we can actually see the sign.
And you can age it, because if you see a sign today
and it hasn't snowed in a while, you know it's within a few days.
But if it snowed recently and it's real fresh,
you know it's within the last snowfall.