I was listening to NPR this morning and they had an interview with Martha Sandweiss, the author of "Passing Strange: A Gilded Age Tale of Love and Deception Across the Color Line". The book is about a well known New York intellectual named Clarence King, who under the assumed name "James Todd" raised a family in New York with an African-American woman originally born into slavery. They met just after the Civil War, and at that time, mixed marriages were extremely rare, and often illegal under state laws. Although fair skinned and blue eyed, King could pass as "black" because people who had only a single great grandparent of African descent, could be considered "black". Apparently that's what "James Todd" told his wife, and also that he worked as a pullman porter on the railroad, and hence was away on travel much of the time.
They didn't mention any mountaineering in the story, but I thought to myself, I wonder if that's the same Clarence King who lead the California Geological Survey and was first director of the USGS, wrote "Mountaineering in the Sierra Nevada," attempted to make the first ascent of Mt. Whitney, and for whom Mt. Clarence King was named. It turns out that it is the same man. It seems he had a very interesting intellectual and social life entirely aside from his life as one of the Sierra's first explorers and dedicated mountaineers.