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Bitter Olive Cort

Cortinarius infractus · Family Cortinariaceae · Updated October 2026

75US records

14states

Novbusiest month

75 US records since 1919 (8 in the last 10 years)

Last seen Sep 11, 2023 (about 3 years ago) in Inyo County, CA, a preserved specimen in International Barcode of Life project (iBOL). Most US records come from California, Washington and Tennessee, and the busiest months are Nov, Oct and Sep. (Data as of October 26, 2026; records can lag by weeks.)

⚠ Never eat a wild mushroom based on this site. We show where fungi have been recorded, nothing more. We never say any mushroom is edible or safe, and you shouldn't decide that from any website, app or photo. Many deadly mushrooms look like harmless ones. If someone may have eaten a wild mushroom, call Poison Control at 1-800-222-1222 right away.

☠ Dangerous genus. The genus Cortinarius includes webcaps containing orellanine. Mushrooms in this group have caused serious or fatal poisonings.

Lookalike warning. Many mushrooms, including deadly ones, closely resemble each other, and the only reliable identification comes from an expert looking at the actual specimen (often with spore prints or microscopy). Never use a name, photo or record count on this page to decide what something is.

When it's recorded

Records by month, all years. Busiest: Nov, Oct, Sep.

Where it's recorded

State	Records	Latest sighting
California	30	Sep 11, 2023
Washington	16	Nov 16, 2001
Tennessee	7	Nov 10, 2019
Wyoming	5	Aug 12, 1999
Colorado	5	Aug 15, 1997
Michigan	2	Sep 23, 2019
New York	2	Oct 13, 2019
Alaska	2	Aug 10, 1998
Idaho	1	Sep 2, 1964
Kansas	1	Sep 17, 1951
Georgia	1	–
North Carolina	1	–

Top counties

Mendocino County, CA (12) · latest Jan 2, 2023
Teton County, WY (5) · latest Aug 12, 1999
Blount County, TN (5) · latest Nov 10, 2019
Clallam County, WA (4) · latest Nov 16, 2001
Thurston County, WA (4) · latest Oct 27, 1970
Humboldt County, CA (3) · latest Dec 17, 2022
Yuba County, CA (3) · latest Jan 13, 1992
Santa Cruz County, CA (3) · latest Jan 11, 2013
Siskiyou County, CA (2) · latest Oct 1, 1983
Marin County, CA (2) · latest Dec 5, 1982

Bring along

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10x hand lens / loupeSee on Amazon

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Spore print paperSee on Amazon

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