UPDATE (Sept. 8) -- All of Nevada will be under a mask mandate starting Friday, according to the state.
Nevada Health Response reported all of Nevada's 17 counties are currently experiencing substantial or high COVID-19 transmission.
Lincoln County is showing a substantial rate while the other counties are showing high rates. Eureka County is for a second week showing high transmission and the county's mandate will begin Sept. 10.
FOX5's original story continues below.
LAS VEGAS (FOX5) -- After being classified as having "high" or "substantial" risk of COVID-19 transmission, two more Nevada counties will be required to enforce a mask mandate starting Friday.
Esmeralda and Lander counties have had a high or substantial rates for two weeks in a row, according to Aug. 31 data from the Centers for Disease Control and Prevention. Per the mandate, the counties must begin mandatory masking on Friday, Sept. 3.
Of the state's 17 counties, all except Mineral County are considered to have high or substantial risk of COVID-19 transmission.
"Mineral County is noted as having a low transmission rate after multiple weeks of a high transmission rate. If Mineral County's transmission level remains 'low' or 'moderate' next week, the mask requirement will only apply to unvaccinated individuals," said a statement from Nevada Health Response.
After being listed as "low transmission" just last week, Eureka County now is classified as high transmission rate and will be required to implement a mask mandate starting Sept. 10 if the rate remains high or substantial for another week.
Unvaccinated individuals are required to wear masks indoors and in outdoor crowded settings, per CDC guidelines and state law.