The broad improvement shown in a Jan. 27 report from the Labor Department reflected a pickup in hiring across the country. Employers nationwide added nearly 3 million jobs last year, the most since 1999. The gains were driven by solid economic growth in spring and summer. During 2014, the national unemployment rate sank to 5.6 percent from 6.7 percent.

In Colorado, which enjoyed the biggest proportional drop in unemployment, healthy hiring lowered its rate to 4 percent from 6.2 percent. Colorado's employers added 62,300 jobs, boosting its payrolls 2.6 percent, the nation's 10th best job gain.

Nathan Kelley, an economist at Moody's Analytics, said Colorado is enjoying an influx of highly educated young people, many of whom are taking jobs at technology-oriented startups and in the aerospace industry. About 58 percent of Boulder's residents over age 25 has a college degree, the highest such proportion in the country.

"People are essentially flooding into this region," he said.

Greater hiring in the state has ranged across most industries, the government said, from manufacturing, construction and professional services to restaurants and hotels.

Other states with sizable drops in unemployment rates last year were: Idaho, whose rate fell to 3.7 percent from 5.6 percent; Ohio, where it fell to 4.8 percent from 7.1 percent; and Illinois, where it dropped to 6.2 percent from 8.9 percent.

Rates rose in only two states last year. The largest was in Louisiana, whose rate jumped to 6.7 percent from 5.4 percent. But that jump occurred because more people moved into the state and didn't find work, not because companies weren't hiring. Louisiana added 29,000 jobs, a 1.5 percent increase. But the number of unemployed people rose to 146,000 from 112,500.

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