You're missing my point. Although attempting to reach Mars may be wise, Fort Bridger is not an effective analogy. By the time we had reached Fort Bridger, human

You're missing my point. Although attempting to reach Mars may be wise, Fort Bridger is not an effective analogy. By the time we had reached Fort Bridger, humans had already traveled across huge territories and had already learned to live in incredibly adverse environments. Perhaps we ought to strive for Mars precisely because it's so different than anything we've done before. But as far as existing known human capabilities go, it's not going to be as obviously possible as Fort Bridger.