Wyoming State Parks Issues Low Water Notice for Glendo and Guernsey Reservoirs

CHEYENNE, Wyo. – Aug. 25, 2025 – Wyoming State Parks is notifying visitors of the annual drawdown of Glendo and Guernsey Reservoirs, managed by the Bureau of Reclamation, as the 2025 irrigation season comes to a close. Water levels will begin to decline shortly after Labor Day and will impact boating and reservoir access through late September.

“This is a routine event that occurs every year once irrigation deliveries end,” said Cassie Wells, superintendent of Guernsey State Park. “We want to make sure our visitors are prepared for the changing water levels and know there are still plenty of ways to enjoy both Glendo and Guernsey State Parks during this time.”

The Bureau of Reclamation advises boaters, recreationists, and irrigators to take proper precautions regarding changing river flows below Glendo and Guernsey Reservoirs and the rapidly changing elevations at both sites. Watercraft owners are encouraged to remove boats early, while ramps remain accessible, to avoid problems caused by falling water levels.

Expected Schedule of Reduced Flows (Bureau of Reclamation)

Labor Day weekend: Glendo Reservoir is expected to be near elevation 4,586 feet (approx. 30% of capacity).
Sept. 2: Outflows from Glendo Reservoir will be reduced to begin lowering Guernsey Reservoir.
Sept. 7: Glendo Reservoir will decline to about 4,584 feet (approx. 30% capacity).
End of September: Outflows will taper to low flow.

Boating Access

The rapid decline in water levels will make boat ramps difficult or unusable. Use extreme caution when leaving watercraft beached overnight or for several hours. Quickly dropping water levels could leave your watercraft high and dry.

Recreation Opportunities

While boating access will be affected, Glendo and Guernsey State Parks remain open for a wide variety of recreation opportunities, including camping, hiking, biking, picnicking, and more. Nearby boating opportunities can be found at Hawk Springs State Recreation Area, Gray Rocks Reservoir, and other locations.

Customers with affected reservations can modify their bookings online at reserve.wyoming.gov or by calling (877) WYO-PARK.

For more information about Glendo and Guernsey State Parks, please visit wyoparks.wyo.gov.

Figure 1: Glendo State Park.

Contact: Steve Horn, Glendo State Park, (307) 735-4433; This email address is being protected from spambots. You need JavaScript enabled to view it., or Cassie Wells, Guernsey State Park, (307) 836-2334; This email address is being protected from spambots. You need JavaScript enabled to view it.