I know that the experienced pilots will already know this, but here's a little cautionary tale for those like me with lots still to learn. Flying north one day into a stiff northerly and trying to keep to the 3500' altitude suitable for my heading, I had to pass over an east-west range with a clearance of only 500'. That's ok, thinks I. It's only a ridge, and I'll have plenty of hight (AGL) on either side of the ridge. Wrong, wrong, wrong. On the southern side of an east-west ridge with a strong northerly blowing over it will be a nice big sink, and I proceeded to lose altitude at an alarming rate as I approached the hills. Full throttle and a best angle climb recovered the situation, but it's not a situation that I want to be in again. I think that from now on, I'll treat the 'correct' cruise altitudes as the guide that they are (below 5000) rather than treating them as the rule that I was. Definitely a case where LSALT was not a safe altitude at all.