FISHING -- An Idaho angler fishing the North Fork of the Clearwater River caught the big one he had to let get away.

On Jan. 8, Larry Warren landed a rainbow trout downstream from Dworshak Dam that would easily be a new state record, but he couldn’t legally keep it.

Any rainbow trout longer than 20 inches with an intact adipose fin is legally considered a steelhead and must be released if caught in waters where steelhead might be found.

Wild steelhead (ocean going cousins of rainbow trout) are protected in the Snake River system under the Endangered Species Act.

Hatchery steelhead are marked by removing the adipose fin. In order to ensure wild steelhead are protected in Idaho waters, Fish and Game requires all rainbow trout longer than 20 inches be released unharmed in waters where wild steelhead naturally return.

Warren landed the monster rainbow and knew he had no choice but to let it go, but he and his fishing companion took photographs and weighed and measured the giant before putting it back in the water.

Their scale put the rainbow at 28.37 pounds. They say it was 32 inches long with an amazing girth of 28.5 inches.

Idaho Fish and Game staffers tested the scale the anglers used, and found it to be relatively accurate, but in order to qualify for a place in Idaho’s record books, a fish must be weighed on a certified scale.

Fish and Game officials say they see photos of giant rainbows landed on steelhead streams from time to time, and anecdotal information suggests these fish are caught more often than some might think.

Once a rainbow trout reaches 20 inches in waters that might contain wild steelhead, it receives protection that rainbows in other waters don’t share. Since 2010, all trout in the Clearwater and North Fork Clearwater were excluded from harvest to protect adult and juvenile steelhead.

Even though this fish was likely stocked as a sterile 10-inch rainbow trout intended for harvest around seven years ago, it has received the same protection as wild rainbows in catch-and-release only waters like the upper Henry’s Fork. If not for that protection, it is unlikely those fish would survive long enough to attain that size.

The fish also had the advantage of living below a dam, giving it access to some pretty easy food coming out of the Dworshak’s turbines.

Regardless of whether this fish could or should have made it into Idaho’s record books, here's the best news: 

• Somebody caught it and got a photo record of the catch.
• Now it's back in the river to make the day for another angler.