Camera - All makes and models.
Camera Manual - important - we know a lot about digital cameras but
certainly don't necessarily know how all the different models work.
Tripod or Monopod (if you have one) (Don't buy one until you are ready
to get a good one) we will have one or two extras to loan.
Extra Camera Batteries and/or Battery Charger for you camera and flash.
Cable release
Bug Spray - for those pesky flies and mosquitoes.
Adequate clothing for the season including rain gear (layers are always
good, even the mornings in the summer can be rather cool).
Extra socks and shoes/boots (in case of rain it's always good to have
an extra pair of dry socks and shoes/boots.)
If you have a variety of lenses, bring them. (If you have a macro lens
or close-filters, this would be great for close-up shots of wildflowers).
Bring a CD or DVD or USB stick to download some of your pictures for
our review and critique session on the overnight trips.