I have successfully used the trustworthy BIC brand lighters above 6000' with no problems in both summer and winter. In cold weather, no matter the elevation, BIC lighters should be kept in an inner coat pocket and they will then work without problem well enough to get your fire or stove going.
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Earth and sky, woods and fields, lakes and rivers, the mountain and the sea, are excellent schoolmasters, and teach some of us more than we can ever learn from books.

John Lubbock