Most camping and backpacking equipment and supplies can be safely and legally packed in your checked and carry on bags. Currently, if you are flying within the US your checked bag can weigh up to 50 lbs. and be 62 inches (w+h+l), so that’s something to monitor closely when packing. Check your airline for checked bag fees. Carry-ons can be up to 22″ x 14″ x 9″ plus you get a personal item, like a purse, small canvas bag, etc– something that will fit under the seat.
If you are flying, renting a car, and tent camping you need to plan clothing, meals, and supplies carefully AND practice packing and weigh your bags to avoid an overweight fee at the airport. The packing list I’m providing is pretty comprehensive– it’s geared toward tent camping and cooking all or most of your own meals. Your list may change depending on HOW you decide to camp or otherwise stay in the park; for example, you might decide not to cook at all– then you don’t have to pack any of the gear for that. Or, you might decide not to tent camp– then you don’t have to worry about those items. Customize the packing list to suite your needs. But don’t skimp on any of the necessary items. You should always hike with the 10 Essentials: navigation, sun protection, insulation, illumination, first aid, fire supplies, repair supplies, nutrition, hydration, and emergency shelter, even if it’s a short day hike.
Again, what you pack depends on exactly HOW you will be camping or staying in the park. Depending on your budget and how much of a true camping experience you want to have, you may want to buy grocery supplies either en route to the park, or when you arrive– or mail your food to General Delivery and pick it up at the post office.
Having lived and worked in the Valley for 2 summers and having traveled back to Yosemite a few times as a visitor, I can say that the stores have a great selection of “grab and go” sandwiches, wraps, snacks, etc. Plus, there are plenty of cafeterias, restaurants, and sandwich shops to choose from. You may decide to combine the “roughing it” of tent camping, with the convenience of not having to cook and clean up! Some of the towns near Yosemite may have outdoor supply stores where you can rent some of your equipment like stove, backpack, etc. Just check online. Yosemite Mountaineering School rents limited equipment like tents, sleeping bags and backpacks. Before you leave, you can also scout out online to find grocery and supply stores that are on your way to the park from the airport, plan a menu, and get all of the food and clean up supplies you need there. You can buy small containers of dish washing liquid, a cheap plastic basin or bus tub for dish washing, ziploc bags or wax paper for wrapping sandwiches, etc.– any of the things that might not fit or might add too much weight to your checked luggage. Yosemite Valley and Tuolumne Meadows have well-stocked stores as well. And don’t forget– if you buy items, like a dish washing basin or even a small inexpensive ice chest, find someone to give it to when you leave instead of throwing it away!
Stoves in my mind are the biggest issue. According to the TSA blog from 2014, “Camp Stoves – These can go in either your carry-on or checked bag. There can be no fuel fumes emitting from the stove. The same goes with propane stoves. Propane tanks are prohibited from both checked and carry-on bags. Empty propane or gas cylinders are allowed in checked or carry-on bags as long as our officers can see inside.” But according to Backpacker Magazine from 2008, “Only new stoves in their original packaging are always allowed. Used stoves must be cleaned of all burn deposits and odors to pass inspection. Liquid-fuel stoves are refused more often than canister burners because they retain more residue. Scrub stoves thoroughly with soapy water, and pack them in checked luggage. To avoid trouble, BACKPACKER editors mail stoves and fuel bottles to outdoor stores at their destination.”
NOTE: I have tried to find as much info online as I can about traveling by plane with a camp stove and information is conflicting. Some people get away with it, some don’t. I think TSA employees may not know all the guidelines. It may be best to make certain your stove is thoroughly clean (NO FUMES), and mail it and a CLEAN, EMPTY fuel can to General Delivery at either the Tuolumne Meadows or Yosemite Valley post office. Otherwise, I would probably find the nearest Walmart, Target, or sporting goods store and just buy a really inexpensive small stove. I have seen some for around $20 and I would give it away when we left.