Anglers who sign up for two specially permitted trout derbies this June at Diamond Lake will have to wash before they come to play.

Anglers who sign up for two specially permitted trout derbies this June at Diamond Lake will have to wash before they come to play.

In line with other changes meant to keep all exotic species out of the lake that was purged of tui chubs less than two years ago, tournament boaters will be required to wash their boats and trailers before joining the two tournaments.

The changes are written into the Umpqua National Forest permits issued to the Black Bird Shopping Center and the Moose Lodge in Medford to run separate tournaments centered at the Diamond Lake Resort.

Black Bird's 11th annual Rainbow 5000 fishing derby is set for June 21. The Moose Lodge's inaugural Diamond Lake Trout Derby is set for June 7-8.

"Boats need to be clear of invasive species before they can get in the water and take part in these tournaments," says Meghan Collins from the Oregon Department of Fish and Wildlife, which joined the Umpqua Forest and several others in the $5.6 million rotenone treatment and restocking of Diamond Lake.

Collins says the washing of boats and trailers after every trip to a river or lake is strongly encouraged to reduce accidental transmission of invasive species like hydrilla and quagga mussels — the latest hitchhiker that is causing environmental damage in Western lakes.

Tournament participants are encouraged to wash their boats and trailers at home before their derbies, Collins says. A portable boat-cleaning station likely will be on hand for those who don't, she says.

Boats and trailers are subject to inspections, Collins says. Anyone who does not comply will not be allowed to take part in the derby, she says.

Anglers not affiliated with the tournaments are not required to wash their boats before entering the lake, she says.

The June 7-8 tournament is hosted by the newly crafted Oregon Fisheries Enhancement Foundation, Inc. The tournament, which costs $100 per person, is billed as a fundraiser to benefit fish-stocking programs and community service projects at Oregon trout-fishing locales.

The tournament includes a Saturday night banquet, a T-shirt and door prizes. Cash prizes are paid to the top 15 people with the biggest trout.

Weigh-ins are scheduled for each afternoon, with a two-fish limit for each weigh-in. If 200 people sign up, organizers are promising a minimum $11,000 cash payout and prizes, with the winners' payments growing depending upon how many more anglers sign up.

For more information on the derby and entry forms, call 541-324-6731 or e-mail kokaneeoregon@hotmail.com.

The Rainbow 5000 derby is identical to last year's first-such derby at Diamond Lake, where Black Bird moved after nine years at Howard Prairie.

Last year, 1,157 people paid the $15 entry fee to fish one day, with the 30 largest trout all earning cash prizes between $50 and $1,000.

Each of last year's winning trout weighed more than 5 pounds and all were part of the original stocking of trophy-sized trout in the first spring after the lake's rotenone treatment.

The same complement of fish stocked last year is scheduled for stocking in the lake again this year.

"With the fish that held over from last year, it should be absolutely fabulous," says Black Bird's Mike McMullen. "Well, it should be if the ice is off the lake by the third weekend in June."