Anyone know why Colorado added the 720 area code originally?

[Letola]

I was reading about Denver phone history and saw that 720 was introduced in the late 1990s. Was population growth really that huge back then, or were businesses driving demand mostly?

[vtmpj]

Yeah, Denver and the surrounding metro area grew really fast during the 1990s, so Colorado started running out of available 303 numbers. Businesses, new residents, cell phones, and internet lines all increased demand at the same time. That’s why 720 was added as an overlay instead of splitting the region apart. I was reading more about the history this website and it explains the expansion pretty well.