Yellow perch illegally stocked in Saratoga Lake
The Wyoming Game and Fish Department says the presence of yellow perch in Saratoga Lake is the result of illegal fish stocking and wants to find the person responsible. Yellow perch are not native to the upper North Platte River watershed.

“Illegal fish introductions are a serious problem throughout the country,” said Alan Osterland, chief of fisheries for the department “This particular introduction is concerning given its location and the potential for the species to spread throughout the North Platte River drainage. Game and Fish takes illegal introductions seriously because of the potentially detrimental impacts to Wyoming’s natural resources.”

Game and Fish is concerned about yellow perch escaping Saratoga Lake into the upper reaches of the North Platte River drainage. They are likely to disperse downstream to other waters in the watershed – including Seminoe, Pathfinder, Alcova, and Gray Reef reservoirs, and the Sweetwater and Medicine Bow rivers – where they could do irreparable damage to the sport fisheries and native fish species. 
Fisheries biologists first discovered yellow perch in Saratoga Lake during routine sampling in 2021. Saratoga Lake is managed as a trout fishery and the department does not stock any cool- or warm-water fish there, including yellow perch.

“This species was not present anywhere within the North Platte River upstream of Glendo Reservoir, so we know it didn’t arrive in Saratoga Lake by happenstance,” said Laramie Region Fisheries Biologist Chance Kirkeeng. “The nearest neighboring populations are in the Upper Laramie River drainage, including Lake Hattie, or in the South Platte drainage, including Crystal and Granite Reservoirs. Someone put these fish in Saratoga Lake — and that has a serious impact on the fishery.” 

A high abundance of stunted yellow perch can result in slower growth rates for managed sportfish in the same water body due to increased competition for food. Game and Fish recently abandoned trout management at Black Hills Power and Light Reservoir near Newcastle following an illegal introduction of yellow perch due to the number of small yellow perch that took over the water. Game and Fish is currently assessing the response at Saratoga Lake. The department has cut off the fresh water flow to the lake to prevent yellow perch from moving into the North Platte drainage. 

“Time and resources spent on illegal fish introductions could be better spent on managing other fisheries in the region,” Osterland said. “This is a frustrating and disappointing discovery for anglers and anyone who enjoys recreating at Saratoga Lake.”

Anglers can help the Game and Fish by harvesting as many yellow perch from Saratoga Lake as they are legally allowed, including fish that are smaller than they might normally choose to keep. The statewide regulation of 50 yellow perch in the creel and possession is currently in place. 

“We’re calling on the public to submit tips and any information about this illegal stocking at Saratoga Lake to Game and Fish,” Osterland said. “This is a public resource that has been seriously impacted.” 

To submit information contact the Stop Poaching Hotline at (1-877-WGFD-TIP). A reward is available and your identity will remain confidential. Illegal fish stockings are a high misdemeanor punishable with up to one year in jail and fines up to $10,000.       
Sara DiRienzo, PIO - (; Robin Kepple, Laramie Region Info. & Education Specialist- (

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