The National Park Service requires that all food requiring refrigeration be maintained throughout the trip at 41 degrees F or lower. Park personnell do stop by and check this! In addition, all leftover food must be bagged and transported out. To keep the customers happy, commercial trips must bring more food than necessary. This will usually result in extra food at the end of each meal. It will be disturbing to some to see perfectly good food (like Salmon steaks) be trashed at the end of the meal.
On our 14 day dory trip with Grand Canyon Explorations, we were fed well.
Samples of our food included (not all included on one day but you can see the variety)
Breakfasts: Eggs, sausage, bacon, fruit, pancakes, french toast, cold and hot cereal, coffee, tea, hot chocolate
Lunches: Usually sandwitches (meat, cheese, peanut butter / jelly), lettuce, tomato, avo, onion, or wraps, cookies, chips, candies, soft drinks, gatoraid
Dinners: (main course listed and all came with some vegetable and rice / potatoe etc)
1) BBQ chicken, salad, veges
2) Shrimp, vegetables, egg rolls, rice
4) Pork Chops, corn bread, beans, salad
6) Halibut, bean salad
7) Chicken, Greek salad, rice
8) Turkey Chili, cabbage salad, corn bread
9) Pork fajitas
10) Pasta with clam sauce, salad, bread, zuchinni
11) Spegetti w/ meatballs, salad
11) Steak, mashed potatoes, veggies
In addition, there was almost always a fine desert made in the Dutch Ovens (see picture above). Oven cooking included corn bread, cakes, brownies, apple cobbler, carrot cake, pineapple upside down cake, peach cobbler.
The boatmen did all the setting up, cooking and pan cleaning. We were only responsible for cleaning our own plate and utinsels. Purified water was always available throughout the day.
Note: Sanitary practices are important on these trips. There will be a hand washing station. Use it before handling any food and before fixing or eating any meal. Definitely wash hands after using the toilet. Because you are travelling closely with a group of people, norovirus epidemics could break out if these practices aren't followed.