03/03/2026
Before Colorado had four area codes, before cell phones fit in our pockets, there was 303.
Established in 1947 as one of the original North American area codes, 303 once covered our entire state, from the Eastern Plains to the Western Slope, from the San Luis Valley to the Northern Front Range. Every call placed from Colorado carried those three digits. It was a simple number that quietly stitched together ranch towns, mining communities, military bases, universities, and growing cities into one connected Colorado.
As our state grew, so did our phone lines and our pride for the 303. New area codes were added, such as 720, 719, 970, 983, and soon 748, but 303 remains the original. It is a reminder of how far we have come and how deeply rooted our shared story is.
On 303 Day, we celebrate more than an area code. Especially this year, as we mark our state’s 150th, and nation’s 250th anniversaries, we celebrate Colorado’s history, its growth, and the people who built this state call by call, generation by generation.
Happy 303 Day, Colorado!
