About Our Site - Boysen State Park

The first white men through the Wind River Canyon were the Ashley Fur Party in 1825. The original dam was built by Asmus Boysen in 1908, for whom the park and reservoir are named. Part of the original dam can still be seen adjacent to the tunnels on the Lower Wind River Campground. Mr. Boysen also built a 710kW power plant at the site. Operations ceased when in 1923 a major flood filled the plant with silt.

The CB&O Railroad went through the canyon in 1911 and the state highway went through in 1925. The existing dam was completed in 1951. Boysen became a state park in 1956.

Original Asmus Boysen Dam Site Located just north of the Lower Wind River Campground. This site also represents the park's northern boundary.

Wyoming Department of Health Issues New Harmful Cyanobacterial Bloom (HCB) Recreational Use Advisories

The Wyoming Department of Health (WDH) has issued a harmful cyanobacterial bloom (HCB) recreational use Toxin Advisory for Boysen Reservoir and Ocean Lake based on data provided by the Wyoming Department of Environmental Quality (DEQ). The WDH is working directly with resource management agencies to ensure that signs are posted at all waterbodies with advisories. Additional details regarding advisory status, including changes to the type of advisory, and other HCB resources can be found at WyoHCBs.org.

The WDH issues recreational use advisories when cyanobacterial cell densities or cyanotoxin concentrations pose a risk to people engaging in swimming or similar water contact activities in areas where cyanobacterial blooms occur. HCBs may also pose a health risk to animals. Bloom Advisories are issued when a HCB is present and toxins may be present. Toxin Advisories are issued when cyanotoxins exceed recreational thresholds. Waterbodies under an advisory are not closed since HCBs may only be present in certain areas and conditions can change frequently. Advisories will remain in place until blooms have fully dissipated and cyanotoxin concentrations are below recreational use thresholds identified in Wyoming's HCB Action Plan.

If you encounter a potential HCB, the Wyoming Department of Health and the Wyoming Livestock Board recommend the following:

Avoid contact with water in the vicinity of the bloom, especially in areas where cyanobacteria are dense and form scums.
Do not ingest water from the bloom. Boiling, filtration and/or other treatments will not remove toxins.
Rinse fish with clean water and eat only the fillet portion.
Avoid water spray from the bloom.
Do not allow pets or livestock to drink water near the bloom, eat bloom material, or lick fur after contact.
If people, pets, or livestock come into contact with a bloom, rinse off with clean water as soon as possible and contact a doctor or veterinarian.

Questions about health effects and recreational use advisories can be directed to Courtney Tillman, Surveillance Epidemiologist, Wyoming Department of Health, at This email address is being protected from spambots. You need JavaScript enabled to view it. or (307) 777-5522. Questions regarding cyanobacteria sampling can be directed to Kelsee Hurshman, Natural Resource Analyst, Wyoming Department of Environmental Quality, at This email address is being protected from spambots. You need JavaScript enabled to view it. or (307) 777-2073.

Current HCB Recreational Use Advisories*

Waterbody Name	Observation or Sampling Location(s)	Advisory Type	Date Issued
Alcova Reservoir	Children's Beach, Oakie Beach, Sandy Beach	Bloom	09/08/2022
Big Sandy Reservoir	East Dam	Bloom	07/14/2022
Bighorn Reservoir	Cottonwood Creek Ramp	Bloom	08/26/2022
Boysen Reservoir	North Swim Beach, Cottonwood Bay	Toxin	09/30/2022
Brooks Lake	Boat Ramp	Bloom	08/04/2022
Buffalo Bill Reservoir	Bartlett Beach	Bloom	09/24/2022
Clendenning Lake	Outlet	Bloom	09/08/2022
Diamond Lake	Northwest Access	Toxin	09/14/2022
Eden Reservoir	South Outlet	Toxin	08/09/2022
Eikster Lake	North Shore	Bloom	09/29/2022
Festo Lake	East Shore	Bloom	09/08/2022
Flaming Gorge Reservoir	Firehole Canyon, Buckboard Ramp	Bloom	08/04/2022
Fontenelle Reservoir	West-Central Ramp	Bloom	08/17/2022
Gillette Fishing Lake	South Shore	Bloom	06/08/2022
Glendo Reservoir	Sandy Beach Dune Campground	Bloom	07/26/2022
Goshen Hole Reservoir	Northwest Ramp	Toxin	07/28/2022
West Granite Springs Reservoir	West Causeway	Bloom	07/28/2022
High Savery Reservoir	North Central Ramp	Bloom	09/03/2022
Keyhole Reservoir	Rocky Point	Bloom	07/28/2022
Kisinger Lakes	NW Shore of NE Kisinger Lake	Bloom	09/08/2022
NE Kisinger Lake	Northwest Shore	Toxin	09/28/2022
Lake Viva Naughton	Southeast Cove	Bloom	08/17/2022
Leazenby Lake	South Access	Toxin	08/09/2022
Lower Jade Lake	Southwest Cove	Bloom	09/29/2022
Miller Lake	Northwest Shore	Bloom	08/01/2022
Murray Lake	Northwest Shore	Bloom	09/08/2022
Ocean Lake	Long Point Ramp	Toxin	09/30/2022
Pathfinder Reservoir	Bishops Point, Diabase Marina	Bloom	08/24/2022
Pelham Lake	Northeast Shore	Bloom	09/29/2022
Rainbow Lake (Shoshone NF)	Southeast Shore	Bloom	08/04/2022
Rainbow Lake on Burroughs Loop (Shoshone NF)	West Shore	Bloom	09/03/2022
Saratoga Lake	East Beach	Toxin	09/14/2022
Scouts Pond	Northwest Dock	Bloom	09/03/2022
Seminoe Reservoir	Sunshine Beach	Bloom	09/28/2022
Sloan Lake	South Beach	Bloom	08/04/2022
Sodergreen Lake	Southeast Shore	Bloom	09/16/2022
Toltec Reservoir	West Ramp	Bloom	07/20/2022
Twin Buttes Lake	South Central Ramp	Bloom	09/03/2022
Upper Brooks Lake	East Shore	Toxin	09/14/2022
Upper Jade Lake	South Shore	Bloom	08/04/2022
V Lake	Shore	Bloom	09/03/2022
Virgin Lake	Northeast Shore	Bloom	09/03/2022
Wheatland Reservoir Number 1	Southwest Ramp	Bloom	09/02/2022
Wheatland Reservoir Number 3	Northwest Ramp	Bloom	07/28/2022
Woodruff Narrows Reservoir	North Ramp	Bloom	07/20/2022

*There may be additional waterbodies with cyanobacterial blooms in Wyoming that WDH is not aware of. Please report such blooms to WDEQ.

Wyoming Department of Health Issues New Harmful Cyanobacterial Bloom (HCB) Recreational Use Advisories

The Wyoming Department of Health (WDH) has issued a harmful cyanobacterial bloom (HCB) recreational use Bloom Advisory for Buffalo Bill Reservoir based on data provided by the Wyoming Department of Environmental Quality (DEQ). The WDH is working directly with resource management agencies to ensure that signs are posted at all waterbodies with advisories. Additional details regarding advisory status, including changes to the type of advisory, and other HCB resources can be found at WyoHCBs.org.

The WDH issues recreational use advisories when cyanobacterial cell densities or cyanotoxin concentrations pose a risk to people engaging in swimming or similar water contact activities in areas where cyanobacterial blooms occur. HCBs may also pose a health risk to animals. Bloom Advisories are issued when a HCB is present and toxins may be present. Toxin Advisories are issued when cyanotoxins exceed recreational thresholds. Waterbodies under an advisory are not closed since HCBs may only be present in certain areas and conditions can change frequently. Advisories will remain in place until blooms have fully dissipated and cyanotoxin concentrations are below recreational use thresholds identified in Wyoming's HCB Action Plan.

If you encounter a potential HCB, the Wyoming Department of Health and the Wyoming Livestock Board recommend the following:

Avoid contact with water in the vicinity of the bloom, especially in areas where cyanobacteria are dense and form scums.
Do not ingest water from the bloom. Boiling, filtration and/or other treatments will not remove toxins.
Rinse fish with clean water and eat only the fillet portion.
Avoid water spray from the bloom.
Do not allow pets or livestock to drink water near the bloom, eat bloom material, or lick fur after contact.
If people, pets, or livestock come into contact with a bloom, rinse off with clean water as soon as possible and contact a doctor or veterinarian.

Questions about health effects and recreational use advisories can be directed to Courtney Tillman, Surveillance Epidemiologist, Wyoming Department of Health, at This email address is being protected from spambots. You need JavaScript enabled to view it. or (307) 777-5522. Questions regarding cyanobacteria sampling can be directed to Kelsee Hurshman, Natural Resource Analyst, Wyoming Department of Environmental Quality, at This email address is being protected from spambots. You need JavaScript enabled to view it. or (307) 777-2073.

Current HCB Recreational Use Advisories*

Waterbody Name	Observation or Sampling Location(s)	Advisory Type	Date Issued
Alcova Reservoir	Children's Beach, Oakie Beach, Sandy Beach	Bloom	09/08/2022
Big Sandy Reservoir	East Dam	Bloom	07/14/2022
Bighorn Reservoir	Cottonwood Creek Ramp	Bloom	08/26/2022
Boysen Reservoir	Lake Side Ramp, Brannon Ramp	Bloom	07/21/2022
Brooks Lake	Boat Ramp	Bloom	08/04/2022
Buffalo Bill Reservoir	Bartlett Beach	Bloom	09/24/2022
Clendenning Lake	Outlet	Bloom	09/08/2022
Diamond Lake	Northwest Access	Toxin	09/14/2022
Eden Reservoir	South Outlet	Toxin	08/09/2022
Festo Lake	East Shore	Bloom	09/08/2022
Flaming Gorge Reservoir	Firehole Canyon, Buckboard Ramp	Bloom	08/04/2022
Fontenelle Reservoir	West-Central Ramp	Bloom	08/17/2022
Gillette Fishing Lake	South Shore	Bloom	06/08/2022
Glendo Reservoir	Sandy Beach Dune Campground	Bloom	07/26/2022
Goshen Hole Reservoir	Northwest Ramp	Toxin	07/28/2022
West Granite Springs Reservoir	West Causeway	Bloom	07/28/2022
High Savery Reservoir	North Central Ramp	Bloom	09/03/2022
Keyhole Reservoir	Rocky Point	Bloom	07/28/2022
NE Kisinger Lake	Northwest Shore	Bloom	09/08/2022
Lake Viva Naughton	Southeast Cove	Bloom	08/17/2022
Leazenby Lake	South Access	Toxin	08/09/2022
Miller Lake	Northwest Shore	Bloom	08/01/2022
Murray Lake	Northwest Shore	Bloom	09/08/2022
Ocean Lake	Long Point Ramp	Bloom	08/26/2022
Pathfinder Reservoir	Bishops Point, Diabase Marina	Bloom	08/24/2022
Rainbow Lake (Shoshone NF)	Southeast Shore	Bloom	08/04/2022
Rainbow Lake on Burroughs Loop (Shoshone NF)	West Shore	Bloom	09/03/2022
Saratoga Lake	East Beach	Toxin	09/14/2022
Scouts Pond	Northwest Dock	Bloom	09/03/2022
Sloan Lake	South Beach	Bloom	08/04/2022
Sodergreen Lake	Southeast Shore	Bloom	09/16/2022
Toltec Reservoir	West Ramp	Bloom	07/20/2022
Twin Buttes Lake	South Central Ramp	Bloom	09/03/2022
Upper Brooks Lake	East Shore	Toxin	09/14/2022
Upper Jade Lake	South Shore	Bloom	08/04/2022
V Lake	Shore	Bloom	09/03/2022
Virgin Lake	Northeast Shore	Bloom	09/03/2022
Wheatland Reservoir Number 1	Southwest Ramp	Bloom	09/02/2022
Wheatland Reservoir Number 3	Northwest Ramp	Bloom	07/28/2022
Woodruff Narrows Reservoir	North Ramp	Bloom	07/20/2022

*There may be additional waterbodies with cyanobacterial blooms in Wyoming that WDH is not aware of. Please report such blooms to WDEQ.

Wyoming Department of Health Issues New Harmful Cyanobacterial Bloom (HCB) Recreational Use Advisories

The Wyoming Department of Health (WDH) has issued a harmful cyanobacterial bloom (HCB) recreational use Bloom Advisory for Brooks Lake, Flaming Gorge Reservoir, Glendo Reservoir, Rainbow Lake, Sloan Lake, Upper Brooks Lake, and Upper Jade Lake based on data provided by the Wyoming Department of Environmental Quality (DEQ). The WDH is working directly with resource management agencies to ensure that signs are posted at all waterbodies with advisories. Additional details regarding advisory status, including changes to the type of advisory, and other HCB resources can be found at WyoHCBs.org.

The WDH issues recreational use advisories when cyanobacterial cell densities or cyanotoxin concentrations pose a risk to people engaging in swimming or similar water contact activities in areas where cyanobacterial blooms occur. HCBs may also pose a health risk to animals. Bloom Advisories are issued when a HCB is present and toxins may be present. Toxin Advisories are issued when cyanotoxins exceed recreational thresholds. Waterbodies under an advisory are not closed since HCBs may only be present in certain areas and conditions can change frequently. Advisories will remain in place until blooms have fully dissipated and cyanotoxin concentrations are below recreational use thresholds identified in Wyoming's HCB Action Plan.

If you encounter a potential HCB, the Wyoming Department of Health and the Wyoming Livestock Board recommend the following:

Avoid contact with water in the vicinity of the bloom, especially in areas where cyanobacteria are dense and form scums.
Do not ingest water from the bloom. Boiling, filtration and/or other treatments will not remove toxins.
Rinse fish with clean water and eat only the fillet portion.
Avoid water spray from the bloom.
Do not allow pets or livestock to drink water near the bloom, eat bloom material, or lick fur after contact.
If people, pets, or livestock come into contact with a bloom, rinse off with clean water as soon as possible and contact a doctor or veterinarian.

Questions about health effects and recreational use advisories can be directed to Courtney Tillman, Surveillance Epidemiologist, Wyoming Department of Health, at This email address is being protected from spambots. You need JavaScript enabled to view it. or (307) 777-5522. Questions regarding cyanobacteria sampling can be directed to Kelsee Hurshman, Natural Resource Analyst, Wyoming Department of Environmental Quality, at This email address is being protected from spambots. You need JavaScript enabled to view it. or (307) 777-2073.

Current HCB Recreational Use Advisories*

Waterbody Name	Observation or Sampling Location(s)	Advisory Type	Date Issued
Big Sandy Reservoir	East Dam	Bloom	07/14/2022
Boysen Reservoir	Lake Side Ramp, Brannon Ramp	Bloom	07/21/2022
Brooks Lake	Boat Ramp	Bloom	08/04/2022
Diamond Lake	Northwest Access	Bloom	07/28/2022
Eden Reservoir	South Outlet	Bloom	07/14/2022
Flaming Gorge Reservoir	Firehole Canyon, Buckboard Ramp	Bloom	08/04/2022
Gillette Fishing Lake	South Shore	Bloom	06/08/2022
Glendo Reservoir	Sandy Beach Dune Campground	Bloom	07/26/2022
Goshen Hole Reservoir	Northwest Ramp	Toxin	07/28/2022
West Granite Springs Reservoir	West Causeway	Bloom	07/28/2022
Keyhole Reservoir	Rocky Point	Bloom	07/28/2022
Leazenby Lake	South Access	Bloom	07/20/2022
Miller Lake	Northwest Shore	Bloom	08/01/2022
Rainbow Lake	Southeast Shore	Bloom	08/04/2022
Saratoga Lake	East Beach	Bloom	07/28/2022
Sloan Lake	South Beach	Bloom	08/04/2022
Toltec Reservoir	West Ramp	Bloom	07/20/2022
Upper Brooks Lake	East Shore	Bloom	08/04/2022
Upper Jade Lake	South Shore	Bloom	08/04/2022
Wheatland Reservoir Number 3	Northwest Ramp	Bloom	07/28/2022
Woodruff Narrows Reservoir	North Ramp	Bloom	07/20/2022