Area codes 385 and 801

Area codes 801 and 385 are area codes in the North American Numbering Plan assigned for service in Salt Lake City and the four surrounding counties of the Wasatch Front in north-central Utah. The numbering plan area includes the counties of Davis, Morgan, Salt Lake, Utah, and Weber. Other included towns than Salt Lake City are Alta, Bountiful, Layton, Murray, Ogden, Orem, Provo, Sandy, South Jordan, Spanish Fork, Taylorsville, West Jordan, and West Valley City. This numbering plan area is located in the Mountain Time Zone.

Area code 801 was one of the original area codes created in 1947, and served the entire state of Utah. Area code 385 is an overlay to the same numbering plan area which commenced service on June 1, 2008.

On September 21, 1997, numbering plan area 801 was restricted to the Wasatch Front, while the rest of Utah was assigned area code 435. This split was originally intended to be a long-term solution. However, the Wasatch Front is not only home to most of Utah's landlines, but also most of its pagers, cell phones and fax machines. As a result, within only two years 801 was close to exhaustion once again. In 2000, the Public Service Commission of Utah (PSC) approved a split for 801 to take effect in 2001, in which Salt Lake County would have retained the 801 area code and the rest of the Wasatch Front would have been assigned area code 385. Conservation measures, such as number pooling, postponed the split for more than seven years.

...
Wikipedia