Are there any kinds of jobs that require programming (or at least competency) but take place outdoors for a significant portion of the time?

As long as I'm fantasizing, an ideal job would involve programming in a high level language like Haskell, F#, or Scala* for, say, 50% of the time and doing something like digging an irrigation trench the rest of the time.

My background: I triple majored in mathematics, philosophy, and history (BS/BA) and have been working as a web developer for the past six years. I love hacking but I'm feeling a bit burned out.

*I only chose these languages as examples since, ideally, I'd want to work among high caliber people... but it really doesn't matter.