The Vermont Department of Fish and Wildlife is working to protect the wild trout population in a stretch of the Dog River by making it a catch and release stream.
State fisheries biologists say the trout population on the lower stretch of the Washington County river has been declining since 2000.
Surveys conducted on the river in the 1990s found abundant populations of wild rainbow and brown trout.
The temporary catch and release order is designed to reduce trout fishing mortality so biologists can determine what is causing the decline in the trout population.
The regulations also require anglers to use artificial lures in the Dog between the Junction Bridge in Montpelier to the Northfield Falls Dam.