It is unlawful for any person on park property to possess, consume, sell or be under the influence of beer; alcoholic beverages; liquor; controlled substances, as defined in Iowa Code Chapter 204; or prescription drugs for which such person does not have a valid prescription, unless otherwise provided by this chapter. Any person violating this section may be ejected from the park area by any police officer and may be fined not to exceed $500 or imprisoned for a period not to exceed 30 days.