Old Dillon Reservoir Fishing Regulations
Summit County, Colorado · 2026 size limits, bag limits, and seasons
Old Dillon Reservoir is a reservoir in Summit County, Colorado. It has its own fishing regulations for 7 species, including Golden Trout, Brook Trout, Brown Trout, and Cutthroat Trout, set separately for 2 sections of the reservoir. These rules replace Colorado's statewide limits on this water.
Map of Old Dillon Reservoir
Fish with special rules on Old Dillon Reservoir
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Old Dillon Reservoir limits by species (2026)
Entire reservoir
| Species | Size limit | Daily bag | Season |
|---|---|---|---|
 Brook TroutArtificial only: Fly/lure only · 1 golden trout limit, minimum 16 inches | 16" min | 2 | Year-round |
 Brown TroutArtificial only: Fly/lure only · 1 golden trout limit, minimum 16 inches | 16" min | 2 | Year-round |
 Cutthroat TroutArtificial only: Fly/lure only · 1 golden trout limit, minimum 16 inches | 16" min | 2 | Year-round |
 Golden TroutArtificial only: Fly/lure only · 1 golden trout limit, minimum 16 inches | 16" min | 2 | Year-round |
 Lake TroutArtificial only: Fly/lure only · 1 golden trout limit, minimum 16 inches | 16" min | 2 | Year-round |
 Rainbow TroutArtificial only: Fly/lure only · 1 golden trout limit, minimum 16 inches | 16" min | 2 | Year-round |
 SteelheadArtificial only: Fly/lure only · 1 golden trout limit, minimum 16 inches | 16" min | 2 | Year-round |
Entire reservoir
| Species | Size limit | Daily bag | Season |
|---|---|---|---|
| All Fish SpeciesArtificial Only | – | – | Year-round |
| Golden Trout | 16" min | 1 | Year-round |
– means no limit is listed for this water. Rules not shown here follow Colorado's statewide regulations.
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Old Dillon Reservoir fishing: common questions
What fish have special regulations on Old Dillon Reservoir?
7 species have rules specific to Old Dillon Reservoir: Golden Trout, Brook Trout, Brown Trout, Cutthroat Trout, Lake Trout, Rainbow Trout, and Steelhead.
What is the golden trout limit on Old Dillon Reservoir?
Golden Trout must be at least 16" to keep on Old Dillon Reservoir (entire reservoir), and the daily bag limit is 2. Rules differ across 2 sections of the reservoir.
What is the brook trout limit on Old Dillon Reservoir?
Brook Trout must be at least 16" to keep on Old Dillon Reservoir (entire reservoir), and the daily bag limit is 2.
What is the brown trout limit on Old Dillon Reservoir?
Brown Trout must be at least 16" to keep on Old Dillon Reservoir (entire reservoir), and the daily bag limit is 2.
Do Colorado statewide fishing rules apply on Old Dillon Reservoir?
Where Old Dillon Reservoir has its own rule for a species, that rule replaces the statewide limit. For species not listed on this page, Colorado's statewide regulations apply. Regulations are set by the Colorado Parks and Wildlife; confirm with the official 2026 regulations before keeping a fish.
Other Colorado waters with special regulations
- South Platte River
- Yampa River
- Colorado River
- White River
- Poudre River · Larimer
- Gunnison River
- Blue River · Grand, Summit
- Roaring Fork River
- Arkansas River · Chaffee , Lake , Fremont , Pueblo
- Animas River · La Plata
- Eagle River · Eagle
- Taylor River
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