Off a seemingly sleepy exit on Interstate 5 in Oregon sits a trippy theme park. Enchanted Forest, which has occupied 20 acres on a hill in the woods between Portland and Eugene for 49 years, is what Disneyland might look like if it had been designed by Ken Kesey and filled with 1960s-era sculptures and animatronic relics of fairy tale characters. It’s unpolished, charming, non-corporate. To some, it’s a beloved family attraction in an otherwise rural area; to others, it’s a slightly creepy but fascinating drug playground in a state…