2 youths encounter an 8' tall bi-pedal figure while on family campout

While camping overnight on desert BLM land, a family member stepped outside to retrieve items from a vehicle and reported seeing a tall humanoid figure walking through a ravine in moonlight. Shortly after, two family members standing outside heard a loud growl and a dirt-scraping sound. Frightened, they ran inside the trailer, and the group remained inside for the night, later finding no tracks due to windblown sand.