Is there a difference? Even Google is of little help.

Much obliged.

They are used similarly. The only difference I can think of is that the use of chute seems broader, at least from what I've seen in route descriptions and maps.

Couloirs are chutes, but not all chutes are couloirs. Couloir means an alpine type chute where snow avalanches run down in the winter or during snow season. Chutes mean not only couloirs, but are also gullies existing on desert and warm tropical mountains as well. I've never heard the desert chutes and gullies referred to as couloirs.

"Couloir" is just a French word, "chute" is English

Couloir is specific to mountains - at least as it is used by English speaking people:

a steep gorge or gully on the side of a mountain

In French it means corridor or passage:

http://dictionary.reverso.net/french-english/couloir

Chute has a more general meaning that can be applied to things other than a "chute" on a mountain:

an inclined plane, sloping channel, or passage down or through which things may pass

A "chute" is something down which objects can slide or fall - laundry chute, garbage chute, etc. It's borrowed from French (means "fall") but has been widespread in American English since the 18th century.

"Couloir" is not nearly as well-known in English, it seems it was picked up by Alpinists in the 19th century and never acquired any broader uses. I think Scott is right: only chutes that are sufficiently alp-like (i.e., snowy) are called couloirs.

I abseil down chutes, but prefer to rappel down couloirs.

Seriously, I generally use couloir for a chute with snow. In NV, we use the term "chute" a lot for features in desert mountains.

To me couloirs are narrow chutes. For example, I could never think of U-Notch or V-Notch on The North Palisade Crest couloirs. But, the narrow chute on the northeast face of Mt. Morrison is a couloir.
If my house had a "laundry chute" it would be a "laundry couloir."

From usage in mountaineering literature, couloir infers snow-filled chute or gully. Couloirs can melt and be clear of snow in late season but typically couloirs are snow filled.

I imagine the use of "couloir" (as someone mentioned above from the french word for corridor) made it into alpinist usage because of the sense that a couloir leads somewhere, ie a feasible route or part of a route. Giving access, if you like. I'm less sure that "chute" is always used in quite the same optimistic way.

couloir is also a word seen in print in moutaineering literature and guide books but seldom used in everyday converstion. It is often mispronounced. It hsould be pronounced koolˈwär, or koo - w(are), First syllable koo, second syllable starts with a w and ends saying the sound of the name of the letter 'r'. I get a kick and kringe when people say "koo-lee-or" or, koo-wy-er.

I've also heard people say Moo-we-er for 'Muir'

dadndave wrote:I imagine the use of "couloir" (as someone mentioned above from the french word for corridor) made it into alpinist usage because of the sense that a couloir leads somewhere, ie a feasible route or part of a route. Giving access, if you like. I'm less sure that "chute" is always used in quite the same optimistic way.

Couloir, Au Cheval, Gendarme, Pied Troiseme, Piolet, and so forth are all widely recognized terms in mountaineering, which makes sense, since mountaineering evolved in the French Alps. Makes me glad I took French in school so I can pronounce these terms correctly.