Trout (rainbow, redband and other stream trout) size limit in Oregon

Closes each year Streams close November 1 through May 21 unless a specific water says otherwise; lakes are open all year

8-inch minimum, two a day, only one over 20 inches — rainbow trout over 20 inches in streams are legally reclassified as steelhead. No limit on brook or brown trout size or number in streams unless a specific water says otherwise. Artificial flies and lures only in streams.

ODFW source page

A slot means the fish must fall between those two numbers. Shorter than 8 inches goes back, and so does longer than 20.

Open all year here, unlike the zone's normal May 22 – October 31 stream season, but with a hard 20-inch ceiling instead of the zone default's one-trophy-fish allowance — this stretch protects its bigger rainbows more, not less. This is the stretch of the Deschutes this site tracks, between Lake Billy Chinook and Benham Falls.

ODFW source page

No Diamond-Lake-specific rainbow trout number exists - it runs on the Southwest Zone's plain lake default (8-inch minimum, 5/day, 3 daily limits in possession, open all year). The one real water-specific rule here is the tiger/brown trout catch-and-release requirement, tied to ODFW's own tui-chub biocontrol stocking program on this lake rather than to a harvest fishery for those species.

ODFW source page

What we left out on purpose

• The lower reaches of the Deschutes River (near its mouth at the Columbia River) are designated a thermal angling sanctuary with possible additional rules from July 15 – September 15, and separate salmon/steelhead seasons apply below Sherars Falls — none of this applies to the Lake Billy Chinook-to-Benham-Falls stretch this site tracks, so it is not modelled here.
• Sturgeon, salmon and steelhead run their own genuinely complex statewide and Columbia River Basin rules (annual tags, Combined Angling Tags, catch-and-release-only sturgeon) that don't apply to this stretch of the Deschutes and are not modelled.
• Oregon's other six zones (Northwest, Southwest, Willamette, Southeast, Snake River, Columbia River, Marine) and their own statewide defaults are not modelled — this site tracks only the Central Zone stretch of the Deschutes River.
• Bull trout are closed to angling everywhere in the Central Zone unless a specific water says otherwise; not modelled since it's a closed, protected species rather than a real bag figure.