The following chart outlines the hatches in the most popular streams and rivers in Southwestern PA and Western Maryland.
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| Casselman River, MD | Size | Savage River, MD | Size | |||
| Black Stone (winter Stone) | March-Mid April | 20-14 | Midges | All Year | 28-18 | |
| Blue Winged Olive | Late March - June | 20-16 | Black Stones | February-April | 20-14 | |
| Grannom (mottled wing caddis) | Late April | 14-12 | Blue Quill | April | 20-16 | |
| Hendrickson | Late April-Early May | 14-12 | Tan Caddis | late April -October | 20-14 | |
| Tan Caddis | Early May-June | 14-18 | Sulphur | Late May-October | 22-12 | |
| Crane Fly (yellow) | Early May-Mid May | 16 | Yellow Sallie | Late May-July | 18-14 | |
| March Brown | Early May -June | 12 | Golden Stonefly | June-July | 14-12 | |
| Sulphur | Mid May - June | 16-12 | Ants | June-October | 20-16 | |
| Light Cahill | Late May- June | 12 | Beetles | June-October | 20-14 | |
| Pink Cahill | Late May | 12 | ||||
| Yellow Sally | Late May | 14 | North Branch of the Potomac River, MD | |||
| Brown Drake | Early June | 10 | Black Stone | 20-14 | ||
| BWO | 16-22 | |||||
| Meadow Run, PA | Tan Caddis | 20-12 | ||||
| Black Stone | March-Mid April | 18-16 | March Brown | 12 | ||
| BWO | Late March-June | 18-20 | Sulphur | 22-12 | ||
| Hendrickson | Late April-Early May | 14-12 | Yellow Sally | 16-14 | ||
| Tan Caddis | Late April-Early June | 14-18 | Golden Stonefly | 12-8 | ||
| March Brown | Early May -June | 12 | Ants | 16-12 | ||
| Sulphur | Mid May - June | 16-12 | Beetles | 16-14 | ||
| Light Cahill | Late May- June | 12 | Hoppers | 12-8 | ||
| Yellow Sallie | Late May-Late June | 14 | ||||
| Green Drake | Late May | 12-10 | Yough River (Below Ramcatt), PA | Size | ||
| Black Stone | March-Mid April | 18-16 | ||||
| Dunbar Creek, PA | BWO | Late March-September | 18-20 | |||
| Black Stone | March-Mid April | 18-16 | Tan Caddis | Mid April - August | 22-14 | |
| BWO | Late March-June | 18-20 | March Brown | Early May -June | 12 | |
| Tan Caddis | Late April-Early June | 14-18 | Slate Drake | Mid May-June & Aug-Sept. | 14-12 | |
| March Brown | Early May -June | 12 | Sulphur | Mid May - October | 22-12 | |
| Yellow Sallie | Late May-Late June | 14 | Light Cahill | Mid May - Mid June | 12 | |
| Green Drake | Late May | 10 | Yellow Sallie | Late May- July | 16-14 | |
| Golden Stone | June-July | 10 | Lime Sallie | June-July | 16-14 | |
| Caenis | June-September | 26-20 | ||||
| Yough River, MD | Golden Stone | June-July | 12-10 | |||
| Black Stone | March-Mid April | 18-16 | Cinnamon Caddis | Late June-August | 16-12 | |
| BWO | Late March-September | 18-20 | Black Caddis | July-September | 18-16 | |
| Tan Caddis | Mid April - September | 22-14 | Midges | July-October | 26-18 | |
| March Brown | Early May -June | 12 | Ants | June-October | 18-14 | |
| Sulphur | Mid May - October | 22-12 | Beetles | June-October | 18-14 | |
| Slate Drake | Mid May-June & Aug-Sept. | 14-12 | Hoppers | July-October | 14-8 | |
| Light Cahill | Mid May - Mid June | 12 | ||||
| Yellow Sallie | Late May- July | 16-14 | ||||
| Caenis | June-September | 26-20 | ||||
| Golden Stone | June-July | 12-10 | ||||
| Cinnamon Caddis | Late June-August | 16-12 | ||||
| Midges | July-October | 26-18 | ||||
| Ants | June-October | 18-14 | ||||
| Beetles | June-October | 18-14 | ||||
| denotes major hatch | ||||||