Cal. Education Code - EDC § 35335. Section 35335.
The governing board of any elementary, high, or unified school district may charge a fee for school camp programs, provided that payment of such fee is not mandatory. No pupil shall be denied the opportunity to participate in a school camp program because of nonpayment of the fee.
The amount of the fee may not exceed the difference between any state, local, or federal funds generated by such a program and the cost of the services actually provided.
For purposes of this section a school camp program is one which is operated pursuant to Article 5 (commencing with Section 8760) of Chapter 4 of Part 6.