OK, now that collective wisdom has prevailed and we're settling for a somewhat shorter version, we have more flexibility in our starting location.

If we start from the Fremont BART station, to the top of Mt Hamilton & back would be about 75 miles roundtrip.

If we start from the vicinity of Alum Rock Park, it would be about 40 miles round trip. But, if that isn't enough and one feels compelled to punish oneself further, Sierra Road is only about 5 miles due north of Alum Rock. Just sayin'.

Any thoughts?