MAMMOTH HOT SPRINGS, Wyo. — Yellowstone National Park’s (YNP) Mammoth Hot Springs Hotel spring opening has been delayed until the wastewater treatment system in the area is completed and operational.
April 28 was originally scheduled as the 2023 Mammoth Hotel opening date, but due to the heavy winter and difficult construction conditions, the new system will not be operational as planned.
In June 2022, historic flooding caused severe damage to the North Entrance Road between Mammoth Hot Springs and the park’s North Entrance in Gardiner, Montana. In addition, a sewer line adjacent to the road that carried wastewater from Mammoth Hot Springs to a sewage treatment plant in Gardiner was ruptured. Staff quickly rerouted the wastewater into percolation ponds used between the 1930s and 1960s, allowing for summer day-use visitation and limited services.
Currently, a new wastewater treatment system is being built to serve the Mammoth Hot Springs area, but this temporary system is not ready to support full hotel operations. Due to an above-average snowpack and cold temperatures this winter, construction of the system has proceeded slower than expected.
YNP staff are working to make the wastewater system operational and ensure it can handle expected use. It’s important that the system is fully functional, safe and meets required environmental standards prior to the park reopening the hotel in Mammoth Hot Springs.
The park has authorized YNP Lodges to open other visitor accommodations earlier than normal to offset inconveniences to displaced guests with existing reservations for the Mammoth Hotel. Those guests will be offered opportunities to rebook at other YNP Lodges properties in the park based on available space.
Although the hotel will be closed to overnight guests temporarily, the hotel’s gift shop, coffee and beverage service and lobby will open as scheduled on April 28. Overnight accommodations will reopen immediately after construction of the wastewater system is completed. The hotel dining room and Terrace Grill will be temporarily closed and regularly scheduled tours departing from Mammoth Hotel will not be available.
The opening of the Mammoth Campground will also be delayed until the wastewater system is operational. The campground closed immediately following the 2022 flood and remains closed because the campground lacks an outlet for wastewater.
All other services in Mammoth Hot Springs will be open including:
- Albright Visitor Center
- General Store
- Post Office
- Medical Clinic
- Gas Station
The North Entrance in Gardiner, Montana, and Northeast Entrance in Silver Gate and Cooke City, Montana, are open to all traffic with no restrictions. Both road corridors were repaired last fall following the flood. All communities near Yellowstone are open year-round, with local businesses offering a wide range of overnight lodging and recreation opportunities.
