Where the CDC Says Masks Should Be Worn Indoors in Colorado

On July 27, the federal Centers for Disease Control and Prevention issued new guidance regarding the use of masks to fight the spread of COVID-19. To combat the growing prevalence of the more transmissible and dangerous Delta variant of the disease, and in recognition of breakthrough cases among the fully vaccinated, officials now recommend that facial coverings be worn by everyone “in public indoor settings in areas of substantial or high transmission” — even if they’ve been immunized.

This recommendation applies to a huge swath of Colorado in terms of both population and geography. According to the latest figures on the Colorado Department of Public Health and Environment‘s COVID-19 dial dashboard, 41 of Colorado’s 64 counties, including the entire Denver metro area, have disease spread that would qualify for mask usage under the CDC’s revised metrics.

But since the feds’ announcement, confusion over the guidelines has been widespread — and Colorado stands as an excellent example of why so many people are baffled.

The current version of the state’s dashboard uses five color codes to designate disease levels. Level Green denotes a cumulative incidence rate of 0-35 cases per 100,000 people, with a 35-100 rate at Level Blue, 100-300 at Level Yellow, 300-500 at Level Orange, and above 500 at Level Red. In contrast, the CDC has just four color-coded rankings for COVID-19 transmission. Blue, or low transmission, includes a one-week cumulative incidence rate per 100,000 people of 0-9.99; the rate is 10-49.99 for Yellow, or moderate transmission; 50-99.99 for Orange, or substantial transmission; and 100 or more for Red, or high transmission.

Only Level Green counties in Colorado are excluded from the new CDC mask guidelines, and as of July 28, just sixteen counties are at that level: Bent, Costilla, Crowley, Custer, Gilpin, Gunnison, Huerfano, Jackson, Kiowa, Logan, Morgan, Otero, Phillips, San Juan, Sedgwick and Washington. Seven Level Blue counties in Colorado have one-week cumulative incidence rates below 50: Lincoln (35.1), Lake (37.1), Fremont (37.8), Ouray (40.5), Rio Grande (44.5), Dolores (49.1) and Yuma (49.7).

That leaves 41 Colorado counties that are considered to have substantial or high transmission of COVID-19 by the CDC’s standards. Among them are 24 that have a one-week cumulative incidence rate that puts them at Level Blue, the state’s second-lowest dashboard level.

Right now, all of metro Denver is at Level Blue, with Boulder County, at 56.9, the lowest, and Broomfield, at 74.9, the highest. Denver proper currently stands at 58.7.

The seventeen Colorado counties that meet the CDC’s description of high transmission include fourteen at Level Yellow, two at Level Orange and one, Mineral County, at Level Red.

Here are the 41 Colorado counties where the CDC recommends that masks be worn in public indoor settings; they’re listed from lowest to highest by one-week cumulative incidence rate on July 28, and are accompanied by their color code on the state’s COVID-19 dial dashboard:

La Plata
51.5 (Colorado Level Blue)

Pueblo
55.9 (Colorado Level Blue)

Boulder
56.9 (Colorado Level Blue)

Prowers
57.7 (Colorado Level Blue)

Denver
58.7 (Colorado Level Blue)

Douglas
63.4 (Colorado Level Blue)

Jefferson
65.5 (Colorado Level Blue)

Arapahoe
66.2 (Colorado Level Blue)

Larimer
68.9 (Colorado Level Blue)

Grand
70 (Colorado Level Blue)

Kit Carson
70.1 (Colorado Level Blue)

Weld
70.1 (Colorado Level Blue)

Adams
70.7 (Colorado Level Blue)

Elbert
71.2 (Colorado Level Blue)

Saguache
73.3 (Colorado Level Blue)

Chaffee
73.7 (Colorado Level Blue)

Broomfield
74.9 (Colorado Level Blue)

Eagle
76.3 (Colorado Level Blue)

Montezuma
84.1 (Colorado Level Blue)

Baca
84.4 (Colorado Level Blue)

Conejos
85.8 (Colorado Level Blue)

San Miguel
85.6 (Colorado Level Blue)

Park
90.2 (Colorado Level Blue)

Teller
98.6 (Colorado Level Blue)

Montrose
100.5 (Colorado Level Yellow)

Routt
101.4 (Colorado Level Yellow)

El Paso
102.4 (Colorado Level Yellow)

Garfield
106.4 (Colorado Level Yellow)

Cheyenne
109.6 (Colorado Level Yellow)

Clear Creek
112.9 (Colorado Level Yellow)

Alamosa
117.4 (Colorado Level Yellow)

Delta
121.9 (Colorado Level Yellow)

Hinsdale
122.1 (Colorado Level Yellow)

Las Animas
131.1 (Colorado Level Yellow)

Mesa
145.9 (Colorado Level Yellow)

Pitkin
157.7 (Colorado Level Yellow)

Archuleta
171.4 (Colorado Level Yellow)

Summit
258.2 (Colorado Level Yellow)

Rio Blanco
348.8 (Colorado Level Orange)

Moffat
369.8 (Colorado Level Orange)

Mineral
523.6 (Colorado Level Red)

We’ve asked Governor Jared Polis’s office if he will issue a new state mandate to align with CDC guidance; until then, the CDC guidelines remain recommendations in Colorado.