I use a LowePro Nova 190 AW shoulder bag that I bought at a local camera shop for about $100.00. I don't make long hikes so a shoulder bag, even loaded, works fine for me. Mine is loaded, holding:
Pentax K-70 w/ Pentax-DA 18-270mm walking-around lens and RC2 quick-release plate
Charger and spare battery
Tabletop tripod w/ RC2 clamp
Speedlight w/ diffuser softbox
Lens cleaning supplies
4 Tiffen filter pouches holding polarizer, 2 sepia filters, and 11 colored filters for monochrome photos (2 filter slots open at the moment)
DIY filter flip book DIY K-70 L-bracket
Remote wireless trigger
Spare batteries for speedlight and wireless trigger
ColorChecker Passport
Manuals for camera body, lens, and speedlight
Kodak Professional Photoguide, 5th Edition
Handbook of Kodak Photographic Filters, 1990 edition
Modified plastic 35mm film canister holding 4 desiccant capsules