An olivaceous-yellow to brown Leprocybe in section Veneti. It is less common than Cortinarius clandestinus, and occurs exclusively in fall. It has more olive-brown tones than C. veneto-occidentalist sensu strictu, which is known only from boreal forests.
Consider Cortinarius clandestinus when you find a Leprocybe with a black-scaley cap and cream to greenish-yellow tones. It one of few Leprocybe that fruit in Spring, making Spring ID easier. However, C.clandestinus may also fruit in fall so it's not that easy!
Cortinarius olsoniae is in Subgenus Telamonia Section Bicolores. This species was named for Joann Olson, a Cortinarius enthusiast from Humboldt County, California, who first collected this species. It was given the provisional name of Cortinarius 'winter blues' in Mushrooms of the Redwood Coast (2016)
Cortinarius anomalodelicatus is a relatively small and slender anomali that is primarily known from the Western USA, Rockies and Alaska.
Cortinarius aff. atrosquamosus
Recent work on Cortinarius section Leprocybe (Ammirati et al, 2020) has described many new species and given us new insight on the diversity of North American species. One of these is Cortinarius arosquamosus, discussed here.