"C2C is a classic Southern CA hike that is said to have the longest continuous gain of any hike in the continental U.S."
I know the Shortys to Telescope climb is longer being 11,500 feet and it's right there in Southern CA.
I realized I never responded to you. I changed the description to include "trail." I think this may distinguish the climb you reference in Death Valley. Apparently one source that says C2C has the longest continuous gain of any trail in the U.S. is Harris, David Money and Harris, Jennifer Money, Afoot and Afield Inland Empire, Wilderness Press, 2009, pp. 231-233. I know I saw this claim many times when I was researching this hike before doing it. But, after seeing your comment, my hiking buddy said we should do the climb you mention.