Trout fishing in Washington hits full speed April 23, when several hundred lowland lakes — stocked with millions of fish — open for a six-month season.

That date also marks the start of the Washington Department of Fish and Wildlife’s (WDFW) first lowland lake fishing derby, which runs through Sept. 6.

To participate on opening weekend, Washington anglers must have an annual freshwater or combination fishing license valid through March 31, 2017. Licenses can be purchased online at https://fishhunt.dfw.wa.gov; by telephone at (866) 246-9453; or at hundreds of licensed dealers across the state. For details on license vendor locations, visit the WDFW website at http://wdfw.wa.gov/licensing/vendors.

WDFW fish hatchery crews have been stocking more than 15 million trout and kokanee in lakes statewide. Those fish include 3.8 million catchable trout, nearly 370,000 larger trout averaging about one pound apiece, and millions of smaller trout that were stocked last year and have grown to catchable size.

Fish stocking details, by county and lake, are available in the annual stocking plan on WDFW’s website at http://wdfw.wa.gov/fishing/plants/statewide.

Anglers parking at WDFW water-access sites are required to display on their vehicle the WDFW Vehicle Access Pass that is provided free with every annual fishing license purchased. The passes are transferable between two vehicles. Anglers who use Washington State Parks or Department of Natural Resource areas need a Discover Pass.