Measles cases rise in Gallatin County as tourist season kicks off; vaccination urged

Although the official start of summer is still days away, tourist season is already in full swing — Main Street is bustling with activity, and traffic is thick along the southern routes to Yellowstone National Park.

But as crowds return and seasonal excitement builds, health officials are urging caution. The Gallatin County Health Department is warning both visitors and residents to stay vigilant as measles cases continue to surface across the county and state.

“With increased travel and tourism, we are certainly mindful of the potential for measles exposure and cases,” said Lori Christenson, a health officer with the Gallatin County Health Department. “While measles is highly contagious, the MMR vaccine remains the best protection, and most residents and visitors are well protected. At the health department, we’re going to continue to monitor the data and provide any timely updates to ensure that everyone stays informed.”

Since Gallatin County’s first confirmed measles cases in mid-April, linked to out-of-state travel, the number has climbed to 12 locally, with 20 cases reported statewide.

Although a case was confirmed June 14, it has been removed from the department’s dashboard, as it involved a visitor from out of state and was counted in their home state’s total rather than Montana’s. According to the department’s website, public exposure may have occurred at the Motel 6 between June 9 and June 13.

Elsewhere in the state, Hill County has reported four cases, while Flathead and Yellowstone counties have each identified two, according to the Montana Department of Public Health and Human Services.

While the resurgence of measles — with April’s case serving Montana’s first confirmed cases since 1990 — is concerning, it’s not entirely unexpected, said Christenson, especially in light of a broader outbreak unfolding nationwide. However, the agency remains committed to halting the spread.

“Our focus really continues to remain on education, accessibility, quick detection and prevention,” she said.

“We do continue to proactively work with our health-care providers to help support that early detection, and we continue to hold vaccination clinics and we’re focused on sharing clear guidance to help individuals make informed choices.”

In addition to offering information about the illness and the effectiveness of the MMR vaccine on the department’s website, Christenson said the site now provides real-time updates on vaccine eligibility for children ages 12 months through 18 years.

Due to the rise in cases in that age group, which accounts for 58% of current cases in the county, children are now able to receive their second MMR dose 28 days after the first, instead of waiting the standard interval.

If community transmission is confirmed, infants ages six to 11 months will also become eligible for an early MMR dose, according to the department’s website.

Once contracted, symptoms typically take seven to 14 days to appear. Early signs include high fever, cough, runny nose and watery eyes. Within a few days, tiny white spots can develop inside the mouth, followed by the measles rash, which usually begins at the hairline and spreads downward to the rest of the body, according to the Centers for Disease Control and Prevention.

Beyond these initial symptoms, measles can lead to severe complications, including ear infections, pneumonia and, in rare cases, acute encephalitis — brain inflammation that results in permanent damage in one of every 1,000 cases. In the U.S., measles-related neurological or respiratory complications lead to death in one to three of every 1,000 cases, according to UChicago Medicine.

Since the global measles outbreak began earlier this winter in the Southwest, nearly 1,200 cases have been reported across 35 states, according to the CDC. The majority have been concentrated in Texas, New Mexico and Kansas.

So far in 2025, the CDC has documented 21 measles outbreaks — defined as three or more related cases — including one in Gallatin County. Of the 1,197 confirmed cases this year, 90% (1,072) are associated with outbreaks.

The CDC reports that 95% of these cases have occurred in individuals who were unvaccinated or whose vaccination status was unknown. An additional 2% were among those with one dose of the MMR vaccine, and 3% occurred in those with two doses. About 12% of all cases have required hospitalization.

Locally, while the exact vaccination status of every case hasn’t been confirmed, Christenson said most infections have been among unvaccinated individuals or those with unknown vaccination status. That said, at least one case has involved a vaccinated person.

Although rare, it is still possible for fully vaccinated individuals to contract measles, Christenson said. However, the measles vaccine is about 97% effective, meaning roughly three out of every 100 vaccinated people could still become infected.

“So that MMR, or measles, mumps and rubella vaccine is very effective,” she said. “The vaccine has been available since the early 60s and scientists in the U.S. and in other countries have carefully studied the vaccine. So we just continue to encourage that vaccines are the most effective way to prevent illness.”

Vaccine appointments and vaccine records can be made and accessed online at the health department’s website. If individuals believe they have the virus or have been exposed, they should contact the health department or their doctor ahead of time to schedule an evaluation, since the virus can stay in the air for up to two hours after an infected person leaves the area.