Measles Outbreak in Montana: New Exposure in Great Falls
GREAT FALLS — Measles continues to spread in Montana, with 17 confirmed cases reported statewide. The Cascade City-County Health Department (CCHD) has now indicated there may have been exposure to the virus in Great Falls.
While no cases have been confirmed among Cascade County residents so far, a person from another county who was infected visited a business in Great Falls, prompting concern. Anyone who was in the building or associated businesses during specific hours may have been exposed.
The CCHD revealed that an individual from Hill County visited the Prospect Heights Medical Center in Great Falls on Tuesday, May 27. Symptoms of measles began manifesting two days later.
Abigail Hill, the health officer for Cascade County, shared her insight: “Since measles is airborne and was present in that building, we consider the entire building to be exposed.”
Potential Measles Exposure in Great Falls
The Montana Department of Public Health & Human Services has clarified that exposure can happen just by being in the same room as someone with measles, even up to two hours after that individual has left.
Individuals who may have been exposed during the Great Falls visit include locations such as Central Montana Orthopedic Specialists, Sun River Health, Atlas Neurology, Dr. Susan Avery’s office, Quest Diagnostics, and Northwest Physicians.
CCHD Guidance
If you suspect you were exposed but don’t hear from CCHD in the subsequent days, you can reach out to them at 406-791-9242 for guidelines. Those with presumed immunity—like people who have adequate vaccination documentation or were born before 1957—do not need to quarantine. They should just monitor for symptoms for 21 days after the exposure. If you lack immunity, however, it’s recommended to stay home for the same period. It’s wise to consult with a healthcare provider about potential risks and consider delaying non-urgent medical appointments for 21 days following exposure.
Initial measles symptoms usually show up about 7 to 14 days after exposure. This might include fever, a cough, a runny nose, red eyes, and white spots in the mouth. Typically, a red rash starts on the face and spreads downward a couple of days after the initial symptoms.
If symptoms do arise, it’s crucial to stay home except for urgent medical care or testing. Contact Benefis Health System at 406-731-8300 to arrange for testing. It’s important not to enter a clinic without prior notice, to allow staff to take necessary precautions.
You’re presumed immune to measles if you have proof of vaccinations for measles, mumps, and rubella (MMR), immunity verified by lab tests, a history of the disease, or were born before 1957. If unsure about your vaccination status, you can call CCHD to check your records.
Measles Cases in Montana
The Montana Department of Public Health & Human Services reports all 17 confirmed cases are among Montana residents, and newly identified cases are currently in isolation.
The cases are distributed across four counties: 10 in Gallatin, three in Hill, two in Flathead, and two in Yellowstone. Two individuals required hospitalization. In April 2025, Gallatin County reported five measles cases—the first confirmed instances in Montana since 1990.
In Hill County, all three reported cases concern unvaccinated children, noted in May. The Yellowstone cases were linked to an adult and a child—both unvaccinated—who fell ill after traveling abroad. Health officials confirmed that both had recovered and were no longer contagious upon returning home.
No additional details have been released regarding the cases in Flathead County.
What to Know About Measles
According to the DPHHS, measles is a highly contagious airborne disease. It can begin with fever, cough, runny nose, red eyes, and a rash that generally appears around 14 days after exposure. The rash typically starts on the face and spreads downward.
This disease can be especially dangerous for infants, who cannot be vaccinated until they are at least 12 months old. Maintaining high vaccination levels in the community is crucial to protect these vulnerable groups.
Globally, measles remains a significant health concern, causing an estimated 300 deaths each day. While cases in the U.S. are rare, there’s been a noticeable uptick in recent years.
The most effective protection against measles is vaccination. The existing recommendations for the MMR vaccine remain unchanged, with two doses being 97 to 99 percent effective in preventing measles.
The DPHHS highlights that measles is so contagious that if one person has it, about 90% of people around them—who aren’t protected—can become infected. An infected individual can transmit the virus even before exhibiting symptoms.
National Context
The CDC reported 1,088 measles cases across 33 states by the end of May. This is a significant jump from just 285 cases last year, marking the highest number in six years.
Texas’s South Plains region has faced the most severe outbreaks, with over 600 cases, primarily affecting children under 19.
If you think you’ve been exposed to measles or are exhibiting symptoms, please reach out to your local health department or primary care provider before making any visits, if possible.
