The 720 area code covers the Denver metro area in north-central Colorado, sharing identical territory with the older 303 code and, more recently, 983, and reaching Denver itself, Aurora (which spans three counties), Lakewood, Arvada, Boulder (home to the University of Colorado's tech and biotech corridor), Westminster, Centennial, and Broomfield across Denver, Arapahoe, Jefferson, Adams, Douglas, and Boulder counties, all in the Mountain Time Zone observing MST at UTC-7 and MDT at UTC-6. Colorado's original 303 area code once covered the whole state; southeastern Colorado including Colorado Springs and Pueblo split off as 719 on March 5, 1988, and the state's northern and western regions including Fort Collins, Grand Junction, Vail, and Aspen split off as 970 on April 2, 1995, narrowing 303 to just the Denver metro, but within a few years cell phones and pagers exhausted even that narrowed supply, leading regulators to introduce 720 on September 1, 1998 as Colorado's first-ever overlay code rather than splitting the metro a third time, a pattern later repeated with the 983 overlay in 2022; because 720 shares territory with 303 and 983, mandatory ten-digit dialing applies to every local call. The article stresses that 720 itself is a legitimate code but frequently spoofed by scammers, citing government-impersonation calls posing as the IRS or Social Security Administration, Wangiri one-ring callback scams, fake utility shutoff threats demanding immediate payment, and neighbor spoofing that mimics a victim's own first six digits, with the same advice to withhold personal or financial information and report suspicious calls to the FTC. It closes by noting outside businesses can lease a local 720 number through a cloud platform to build credibility across Denver, Boulder, and the Front Range without a physical Colorado office.