The top four companies in Outside magazine’s annual ranking of The 100 Best Places to Work in 2017 are from Colorado.

In fact, Colorado dominated the annual ranking, nabbing 41 of the top 100 spots. That’s up from 37 last year and 30 the year before that.

The ranking is based on a survey of employees about factors ranging from engagement and work environment to corporate culture, policies and perks.

The top four places are:

  1. Forum Phi Architecture in Aspen. The firm’s 21 employees earn an average salary of $65,819 and they get unlimited vacation days after one year.
  2. GroundFloor Media in Denver. The company’s 18 employees make an average of $93,300 a year and receive unlimited paid time off after one year.
  3. Avid4 Adventure in Boulder. The camp operator did not disclose how much its 20 employees earn, but they do get unlimited paid time off.
  4. WhippleWood CPAs in Littleton. The accounting and business consulting firm’s 25 employees earn an average of $87,800 a year and receive 16 days of paid time off after one year.

Also landing in the top 10 are Pax8 in Denver, coming in at No. 6, and Room 214 in Boulder at No. 7.