Aden is a locality in the County of Forty Mile No.
[1] The port of entry is located where Alberta Highway 880 continues as Secondary Highway 409 within Liberty County, Montana.
The locality takes its name from Aden, a port city in Yemen.
Winters are long and dry, but only mildly cold, while summers are short but very warm.
Precipitation is low, with an annual average of 407 mm, and is concentrated in the warmer months.