Las Colinas Tienen Ojos (1977)

The veteran Cleveland-based police officer Big Bob Carter has been forced into early retirement due to suffering from a heart disease. He takes his family (including his son-in-law and his infant granddaughter) to a road trip towards California. In Nevada, they meet the elderly gas station owner Fred, and Lynne Carter notices that the man is hiding stolen goods in his private residence. Fred convinces Bob to take a desert detour through a more scenic route. Due to hidden spikes on the road, the Carters are stranded in the desert. Bob walks his way back to the gas station, where Fred tells him a story about his estranged son Jupiter and his grandchildren. They have reportedly settled in the desert, where they survive by cannibalizing travelers and stealing supplies. Shortly later, Jupiter kills both Fred and Bob. The desert dwellers have plans for the rest of the Carters.