Colorado companies have landed the top four spots in Outside magazine's annual ranking of the best places to work, and six of the top 10.

Overall, Colorado increased its dominance in the annual ranking of the nation’s happiest workplaces, taking 41 of the 100 spots, up from 37 last year, 30 the year before and 28 the year before that.

The Santa Fe-based magazine compiled the ranking by surveying employees about factors ranging from engagement and work environment to corporate culture, policies and perks and role satisfaction.

“Some companies go beyond kegerators and ping-pong — from unlimited vacation time to powder days, these are the places that know how to treat their employees,” Outside says of its ranking.

Read more at the Denver Business Journal: