This is not an exhaustive list.

For field work.

• day pack.
• at least two water bottles of good capacity.
• hat.
• sun block.
• field note book and writing implement.
• clip board optional but helpful
• your maps.
• sun glasses.
• good field boots with ankle support.
• hand lens optional but suggested.
• camera optional, but highly recommended.

For other times:

• photo ID.
• any necessary medicines, or prescriptions.
• sleeping bag and pad.
• appropriate clothes. The layer approach works well. It could rain.
• swim suit (if plan to use swimming pool).
• eating implements.
• small flashlight.
• laundry bag of some type.
• a towel.
• toiletries.

Back packs or duffel bags work well for packing away in the cars. Suitcases do not.