Rob V. and I climbed Mt. Diablo via the Back Creek Trail (from Clayton) the day after my 51st birthday. It was a gorgeous day, albeit with some haze from a fire up in Napa. The way up was fast and easy; the way down, somewhat painful.
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I actually hadn't put in a quarter

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Notice new 'Old Geezer' wrap-around sunglasses

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South peak in background

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Rob, looking a little knackered