To keep our little girl busy I bought some toys for $1 each. We gave one to her a day when we wanted a little quiet break to ourselves. These all worked great! We even had a laser light show one night in our cabin from our little girl dancing with the glow stick in the dark! A state park is a great way to entertain a toddler for a small amount of money.
Here are some other small toy camping ideas:

Lisa Rusczyk is the founder of Charlie The Cavalier (a blog about Charlie her dog, and her friends, family and home) and founder of 50ThingsToKnow. Lisa is a Doctoral student in Educational Leadership who happened to start writing her first book 50 Things to Know Before Having a Baby after her little girl was born. Her book sold over 1,000 copies in the first year on Amazon. Today, she has over 10 books and helps others self-publish. Further, she shares this information with the public via this blog, Facebook, YouTube, Pinterest, Twitter, and recently on a local television station. Lisa knows that like her there are a lot of people who would like concise information on a topic in one digital location. Lisa is known for her simple and effective tips.