This has also been my experience and maybe good luck with bears in the Sierra
Nevada. We like to camp at Bucks Lake in Plumas county, which has a history of
nighttime bear visits in campsites. No food lockers, bear-proof or otherwise.
We encountered a bear there just this past June. I had placed a cooler and a
food bin up on top in the luggage carrier of our westy. It was late-night
laziness that caused me to slide a second, shorter food bin under the van from
the passenger side. My wife woke me after hearing the bear bumping the van, and
he had pulled the box out and just made off with it by the time I climbed out.
It was my hail of rocks that caused him to drop the box and run splashing into
the lake with nothing but a bag of marshmallows, missing out on some choice
eats. The next morning I told our girls that I had ridden him and pulled his
ears until he dropped the goods. They believed it.

The campers nearest us had encountered a bear from inside their tent trailer
before we arrived. They stored food inside, and claimed that they scared the
bear off by whacking against the canvas side when they heard him bumping around
out there. They had been camping there annually for years this way.

Lacking bear-proof lockers, my vote is with the top of the van or maybe inside
as a last resort. -Phil

> It is my personal opinion, at least with regards to the black bears in the
> Sierra Nevada, that if you are in the van or the tent, the bears will not
> bother you.  I have spent many, many nights in my tent with my food under
> my head in busy bear areas in the Sierra and have never been bothered.
> YMMV
>
> Ive also left my rig full of grub while on climbs in Yosemite Valley and
> have never had a problem.  Yes, if there is a bear box USE IT, but thats
> not always an option.  I just make sure everything is in the cupboards and
> that all the curtains are drawn.  When the bear cant see the food or
> cooler, he is much less likely to break into the car.
>
> Probably just jinxed myself...
>
>
> jg