| Amphinemura claassenia Wu, 1935 | |
| Arsapnia coyote Nelson & Bau..., 1987 | Coyote Snowfly |
| Arsapnia pileata Jewett, 1966 | Birdhead Snowfly |
| Arsapnia sequoia Nelson & Bau..., 1987 | Sequoia Snowfly |
| Arsapnia teresa Claassen, 1924 | Bernardino Snowfly |
| Arsapnia tumida Claassen, 1924 | Swollen Snowfly |
| Arsapnia utahensis Gaufin & Jewett, 1962 | Utah Snowfly |
| Bolshecapnia maculata Jewett, 1954 | Spotted Snowfly |
| Brachyptera vanduzeei (Jewett, 1956) | ⇒ Oemopteryx vanduzeea Claassen, 1937 |
| Calileuctra dobryi Shepard & Ba..., 1995 | Elsmere Needlefly |
| Calileuctra ephemera Shepard & Ba..., 1995 | Napa Needlefly |
| Capnia barberi Claassen, 1924 | Plumas Snowfly |
| Capnia californica Claassen, 1924 | California Snowfly |
| Capnia confusa Claassen, 1936 | Widespread Snowfly |
| Capnia coyote (Nelson & Bau..., 1987) | ⇒ Arsapnia coyote Nelson & Bau..., 1987 |
| Capnia elongata Claassen, 1924 | Cascades Snowfly |
| Capnia excavata Claassen, 1924 | Saddleback Snowfly |
| Capnia fialai Nelson & Bau..., 1990 | Humboldt Snowfly |
| Capnia giulianii Nelson & Bau..., 1987 | Whitney Snowfly |
| Capnia glabra Claassen, 1924 | Smooth Snowfly |
| Capnia gracilaria Claassen, 1924 | Slender Snowfly |
| Capnia hitchcocki Nelson & Bau..., 1987 | Arroyo Snowfly |
| Capnia inyo Nelson & Bau..., 1987 | Inyo Snowfly |
| Capnia lacustra Jewett, 1965 | Lake Snowfly |
| Capnia lineata Hanson, 1943 | Straight Snowfly |
| Capnia maculatus | |
| Capnia mariposa Nelson & Bau..., 1987 | Mariposa Snowfly |
| Capnia melia Frison, 1942 | Northwest Snowfly |
| Capnia mono Nelson & Bau..., 1987 | Mono Snowfly |
| Capnia ophiona Nelson & Bau..., 1987 | Snakehead Snowfly |
| Capnia palomar Nelson & Bau..., 1987 | Palomar Snowfly |
| Capnia pileata (Jewett, 1966) | ⇒ Arsapnia pileata Jewett, 1966 |
| Capnia promota Frison, 1937 | Pacific Snowfly |
| Capnia quadrituberosa Hitchcock, 1958 | Four-knobbed Snowfly |
| Capnia regilla Nelson & Bau..., 1987 | Royal Snowfly |
| Capnia saratoga Nelson & Bau..., 1987 | Saratoga Snowfly |
| Capnia scobina Jewett, 1966 | Rasp Snowfly |
| Capnia sequoia (Nelson & Bau..., 1987) | ⇒ Arsapnia sequoia Nelson & Bau..., 1987 |
| Capnia shasta Nelson & Bau..., 2009 | Shasta Snowfly |
| Capnia shepardi Nelson & Bau..., 1987 | Yuba Snowfly |
| Capnia sierra (Nebeker & Ga..., 1965) | ⇒ Utacapnia sierra Nebeker & Ga..., 1965 |
| Capnia spinulosa Claassen, 1937 | San Gabriel Snowfly |
| Capnia teresa (Claassen, 1924) | ⇒ Arsapnia teresa Claassen, 1924 |
| Capnia tumida (Claassen, 1924) | ⇒ Arsapnia tumida Claassen, 1924 |
| Capnia umpqua Frison, 1942 | Umpqua Snowfly |
| Capnia utahensis (Gaufin & Jewett, 1962) | ⇒ Arsapnia utahensis Gaufin & Jewett, 1962 |
| Capnia valhalla Nelson & Bau..., 1987 | Viking Snowfly |
| Capnia ventura Nelson & Bau..., 1987 | Ventura Snowfly |
| Capnia yoloensis (Baumann & Ga..., 1970) | ⇒ Mesocapnia yoloensis Baumann & Ga..., 1970 |
| Capnia yosemite Nelson & Bau..., 1987 | Yosemite Snowfly |
| Capnura wanica Frison, 1944 | Intermittent Snowfly |
| Despaxia augusta Banks, 1907 | Autumn Needlefly |
| Doddsia occidentalis Banks, 1900 | Western Willowfly |
| Eucapnopsis brevicauda Claassen, 1924 | Short-tailed snowfly |
| Isocapnia abbreviata Frison, 1942 | Shortlimb Snowfly |
| Isocapnia eichlini Zenger & Bau..., 2004 | Napa Snowfly |
| Isocapnia grandis Banks, 1907 | Giant Snowfly |
| Isocapnia mogila Ricker, 1959 | Irregular Snowfly |
| Isocapnia spenceri Ricker, 1943 | Chilliwack Snowfly |
| Isocapnia vedderensis Ricker, 1943 | Vedder Snowfly |
| Jurataenionema stigmaeus ♰ Y. S. Liu, 2007 | |
| Lednia sierra Baumann & Ko..., 2010 | Sierra Forestfly |
| Lednia tumana Ricker, 1952 | Meltwater Forestfly |
| Leuctra sara (Claassen, 1937) | ⇒ Paraleuctra sara Claassen, 1937 |
| Leuctra schistocerca Zwick, 1971 | |
| Malenka bifurcata Claassen, 1923 | Forked Forestfly |
| Malenka biloba Claassen, 1923 | Two-lobed Forestfly |
| Malenka californica Claassen, 1923 | California Forestfly |
| Malenka cornuta Claassen, 1923 | Horned Forestfly |
| Malenka depressa Banks, 1898 | Bluntlobe Forestfly |
| Malenka flexura Claassen, 1923 | Twisted Forestfly |
| Malenka marionae Hitchcock, 1958 | Sagehen Forestfly |
| Malenka tina Ricker, 1952 | Tiny Forestfly |
| Megaleuctra sierra (Fields, 1977) | ⇒ Megaleuctra stigmata Banks, 1900 |
| Megaleuctra stigmata Banks, 1900 | Giant Needlefly |
| Mesocapnia aptera Lee & Baumann, 2011 | Wingless Snowfly |
| Mesocapnia bakeri Banks, 1918 | Pomona Snowfly |
| Mesocapnia bulbosa Nelson & Bau..., 1990 | Bulbous Snowfly |
| Mesocapnia frisoni Baumann & Ga..., 1970 | Plains Snowfly |
| Mesocapnia lapwae Baumann & Ga..., 1970 | Lapwai Snowfly |
| Mesocapnia porrecta Jewett, 1954 | Stretched Snowfly |
| Mesocapnia projecta Frison, 1937 | Spined Snowfly |
| Mesocapnia werneri Baumann & Ga..., 1970 | Sabino Snowfly |
| Mesocapnia yoloensis Baumann & Ga..., 1970 | Yolo Snowfly |
| Moselia infuscata Claassen, 1923 | Hairy Needlefly |
| Moselia zonata Stark & Harr..., 2016 | Banded-wing Needlefly |
| Nemoura arctica Esben-Petersen, 1910 | Arctic Forestfly |
| Nemoura besamesta | |
| Nemoura columbiana (Claassen, 1923) | ⇒ Zapada columbiana Claassen, 1923 |
| Nemoura delicatula (Claassen, 1923) | ⇒ Podmosta delicatula Claassen, 1923 |
| Nemoura foersteri (Ricker, 1943) | ⇒ Ostrocerca foersteri Ricker, 1943 |
| Nemoura nevadensis (Claassen, 1923) | ⇒ Soyedina interrupta Claassen, 1923 |
| Nemoura oregonensis (Claassen, 1923) | ⇒ Zapada oregonensis Claassen, 1923 |
| Nemoura spiniloba Jewett, 1954 | Spiny Forestfly |
| Oemopteryx leei Baumann & Ko..., 2009 | Headwater Willowfly |
| Oemopteryx vanduzeea Claassen, 1937 | Seep Willowfly |
| Oemopteryx vanduzeei Claassen, 1937 | |
| Ostrocerca foersteri Ricker, 1943 | Cascades Forestfly |
| Paracapnia baumanni Kondratieff ..., 2010 | Mendocino Snowfly |
| Paracapnia boris Stark & Baumann, 2004 | Colusa Snowfly |
| Paracapnia disala Jewett, 1962 | Dirty Snowfly |
| Paracapnia humboldta Baumann & J...., 2007 | Redwood Snowfly |
| Paraleuctra andersoni (Harper & Wil..., 1985) | ⇒ Pomoleuctra andersoni Harper & Wil..., 1985 |
| Paraleuctra divisa Hitchcock, 1958 | California Needlefly |
| Paraleuctra forcipata Frison, 1937 | Bullshorn Needlefly |
| Paraleuctra occidentalis Banks, 1907 | Western Needlefly |
| Paraleuctra sara Claassen, 1937 | Appalachian Needlefly |
| Paraleuctra vershina Gaufin & Ricker, 1974 | Summit Needlefly |
| Perlomyia collaris Banks, 1906 | Black Needlefly |
| Perlomyia utahensis Needham & Cl..., 1925 | Swamp loosestrife |
| Podmosta delicatula Claassen, 1923 | Delicate Forestfly |
| Pomoleuctra andersoni Harper & Wil..., 1985 | Oregon Needlefly |
| Prostoia besametsa Ricker, 1952 | Banded Forestfly |
| Sierracapnia barberi Claassen, 1924 | Plumas Snowfly |
| Sierracapnia hornigi Baumann & Sh..., 1984 | Esmeralda Snowfly |
| Sierracapnia mono Nelson & Bau..., 1987 | Mono Snowfly |
| Sierracapnia palomar Nelson & Bau..., 1987 | Palomar Snowfly |
| Sierracapnia shepardi Nelson & Bau..., 1987 | Yuba Snowfly |
| Sierracapnia yosemite Nelson & Bau..., 1987 | Yosemite Snowfly |
| Soyedina interrupta Claassen, 1923 | Broken Forestfly |
| Soyedina nevadensis Claassen, 1923 | Nevada Forestfly |
| Soyedina producta Claassen, 1923 | Knobbed Forestfly |
| Taenionema atlanticum Ricker & Ross, 1975 | Atlantic Willowfly |
| Taenionema californicum Needham & Cl..., 1925 | California Willowfly |
| Taenionema grinneli Banks, 1918 | |
| Taenionema grinnelli Banks, 1918 | Angeles Willowfly |
| Taenionema jeanae Baumann & C...., 2007 | Silverado Willowfly |
| Taenionema kincaidi Hoppe, 1938 | Pale Willowfly |
| Taenionema pacificum Banks, 1900 | Pacific Willowfly |
| Taenionema pallidum Banks, 1902 | Common Willowfly |
| Taenionema raynorium Claassen, 1937 | Yosemite Willowfly |
| Taeniopteryx nivalis Fitch, 1847 | Boreal Willowfly |
| Utacapnia columbiana Claassen, 1924 | Columbian Snowfly |
| Utacapnia sierra Nebeker & Ga..., 1965 | Sierra Snowfly |
| Utacapnia tahoensis Nebeker & Ga..., 1965 | Tahoe Snowfly |
| Visoka cataractae Neave, 1933 | Cataract Forestfly |
| Zapada cinctipes Banks, 1897 | Common Forestfly |
| Zapada columbiana Claassen, 1923 | Columbian Forestfly |
| Zapada cordillera Baumann & Ga..., 1971 | Cordilleran Forestfly |
| Zapada frigida Claassen, 1923 | Frigid Forestfly |
| Zapada haysi Ricker, 1952 | Intermountain Forestfly |
| Zapada oregonensis Claassen, 1923 | Oregon Forestfly |
