I read in the Reader's Reviews that Brunton and other butane lighters just will not work above 10,000 ft. BOY! I'm glad I happened on this review thread.
I'm climbing Mt. Charleston this weekend (11,990+ ft.) and camping at 10,000 ft. I'll be sure to carry a Zippo lighter that I KNOW will work above 10,000 ft. Sometimes old tech ain't all that bad.
Eric
