Day Hike Packing List for California Trails — What Goes in the Pack

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This is the packing list I actually use. Not the one that covers every theoretical scenario — the practical items that earn their weight on a California day hike, adjusted for the conditions California actually presents.

Water

3 liters minimum on non-summer hikes. 4 liters for summer or fully exposed terrain.
Hydration bladder (2L) + one 1L bottle — the bottle lets you track consumption and provides a backup.
Nuun electrolyte tabs (2–3 per day) — not optional on hot days. Plain water without electrolytes risks hyponatremia on long sweat days.
Sawyer Squeeze water filter — for any Eastern Sierra hike or trail with reliable water sources.

Food

200–300 calories per hour of planned hiking. A 6-hour hike needs 1,200–1,800 calories.
Bring more than you think you need — altitude and heat both suppress appetite before they suppress physical function.
What works: trail mix, RXBar or Clif bars, dates and peanut butter, crackers with hard cheese or salami, dried mango for the summit.
What doesn’t: anything that melts, anything requiring cooking, packaging that creates multiple pieces of trash on trail.

Navigation

AllTrails with offline maps downloaded before you leave the car. (AllTrails+ required for offline →)
Phone in airplane mode to preserve battery once you’re in the mountains.
External battery pack — 10,000mAh minimum for full-day hikes.
Know the trailhead coordinates before you go — cell service disappears fast in the San Gabriels.

Sun and Weather Protection

UPF 50+ sun hoody — on your body, not in the pack.
Wide-brim hat and polarized sunglasses.
Sunscreen SPF 50 — face and exposed skin, reapply every 2 hours.
Lightweight puffy jacket — any hike above 8,000 feet or with a long summit section.
Wind shell — Santa Monica ridgelines and Eastern Sierra exposed terrain.

First Aid and Safety

Blister treatment: Leukotape applied before a hot spot becomes a blister. This is the move. Band-Aids are a blister treatment. Leukotape is blister prevention.
Ibuprofen, antihistamine, elastic bandage.
Emergency whistle — weighs nothing, genuinely useful for signaling without voice.
Mylar emergency blanket — prevents hypothermia in an unexpected overnight.
Headlamp with fresh batteries — starting early or ending late are both real possibilities.

Miscellaneous That Actually Matters

Trekking poles — for anything with significant descent or 10+ miles. Non-negotiable on Mount Wilson or any Eastern Sierra trail.
Trowel and waste bags — Leave No Trace. There are no bathrooms on most trails above the trailhead.
Cash — Adventure Pass trailheads, some parking lots still cash-only.

Dog Adjustments

Collapsible dog bowl — you cannot pour water into a dog effectively.
Roughly 1.5 liters of dog water for every 1 liter you bring for yourself (adjust for dog size).
Poop bags — always, even on trails where bags are provided.

See June’s Dog Report on every trail review for trail-specific dog needs.

Eastern Sierra / High Altitude Additions

Warm hat and gloves — even in September, summit temps drop dramatically.
Rain jacket — afternoon thunderstorms in the Sierra are real and fast-moving.
Bear canister — required for overnight, recommended for day hikes in active bear areas.
Altitude medication if prescribed — take per doctor instructions, never day-of.

What to Leave at Home

Camp stove, more than one change of clothes, tent (unless explicitly planning emergency contingency), anything over 1.5 lbs I won’t use on the specific terrain I’m hiking. Every extra pound is extra energy on the descent. California summer hiking is not the place to carry theoretical gear that earns its weight one time in ten.