Khao Yai is generally safe for solo female travelers. It's a very tourist-friendly destination with locals often willing to assist you. Thai people are known for their hospitality and Khao Yai is no exception. The area is relatively crime-free. However, as with any travel, stay alert, especially at night. The main concern for solo female travelers might be the wildlife in Khao Yai National Park - always stay with a tour group or guide while exploring.