# US western measles outbreak 2026

> Live situation record from CLSTR: https://clstr.news/situations/us-western-measles-outbreak-2026
> Updated: 2026-07-31T00:58:27.000Z. Sources: 2. Developments: 2.

In early July, Teton County, Wyoming declared a local emergency after confirming a measles outbreak, signaling heightened concern in the region. By the end of the month, Montana reported no active measles cases, marking a stark contrast to neighboring states where dozens to hundreds of infections persisted. While Montana celebrated a mid‑summer absence of measles, the state also faced expanding wildfires, underscoring simultaneous public‑health and environmental challenges across the western United States.

## Timeline

### 2026-07-31: Montana Reports Zero Measles Cases Mid‑Summer as Fires Rage and Foster Care Policy Shifts

Montana reports no measles cases mid‑summer, ends the “orphan tax” for foster children, and fights two growing wildfires covering 4,000 and 900 acres.

2 sources. https://clstr.news/cluster/montana-reports-zero-measles-cases-midsummer-as-fires-rage-and-foster-care-policy-shifts

### 2026-07-11: Teton County, Wyoming Declares Local Emergency Over Measles Outbreak

Teton County, Wyoming, declared a local emergency after three measles cases at Colter Bay Village; a third adult case was confirmed, prompting vaccination and exposure warnings.

2 sources. https://clstr.news/cluster/teton-county-wyoming-declares-local-emergency-over-measles-outbreak

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Cite as: US western measles outbreak 2026. CLSTR, https://clstr.news/situations/us-western-measles-outbreak-2026