What is the name of a move made in the late 1970s about a family that goes hiking and goes into a cave and when thay come out they find that all of humanity has been reduced to ashes?

Where Have All The People Gone? was a made for TV movie that was broadcast in 1974. It stared Peter Graves, Kathleen Quinlan and Verna Bloom. This movie speculates on what would happen if a massive solar flare erupted and anyone whom was not in some sort of shelter dies from exposure to the solar radiation.

THIS IS ANOTHER WEIRD LINK THAT IS VALID BUT WILL NOT WORK WITH THE LANGUAGE ON FLUTHER (long live Fluther!) just copy and paste it

http://en.wikipedia.org/wiki/Where_Have_All_The_People_Gone%3F

The movie you are looking for is “Where Have All the People Gone?” a 1974 TV movie starring Peter Graves as the father, and Kathleen Quinlin as the daughter.

The plot involves a family that has gone camping in the mountains with a friend. The mother returns home, and the rest of the family go into a cave. A bright light (a solar flare) and earthquake occur, and when the family comes out, there is no one around in the nearest town. Instead, there are people’s clothes with white powder spilling out of them. All the animals go wild, and eventually the friend, who saw the light, dies. They eventually find some other survivors. Apparently there are some other solar flares, and the survivors discover they are immune to the effects. Like many other dystopic SF films of the time period, it plays on fears of catastrophe (esp. nuclear).

It clearly is a film with a cult following that stays with those who saw it (esp. if they were children), to judge by the commentary on the internet movie data base. Recently released DVD of unknown quality combined with a bad 1976 horror movie, “Embryo.”

Embryo/Where Have All The People Gone DVD
Category Science-Fiction/Fantasy
Studio KRB Music
All Time Sales Rank 63453
CD Universe Part# 7069109
Discs 1
Street Date Mar 31, 2006

http://movies.yahoo.com/movie/1800134934/info
http://www.imdb.com/title/tt0072400/