Hi

I'm looking for a movie I saw in the 80's.  These are the facts I recall:

Four college students drive into the backwoods of some dismal southern
region to check on property one of them has inherited.

As they drive through a poverty-stricken shanty-town, one of them
says, upon seeing several sets of twins, "More Gemini."

There is a crazy inbred family in the woods.  They kill the college
kids one-by-one until only one of the girls is left.  One of the crazy
inbred sons picks her up (presumably to rape her and eat her brain or
something) and she rams her fist down his throat and chokes him to
death.

Incredibly unique ending.  What's the name of the movie?

I'm certain your movie is "Just Before Dawn". This is the only movie I
know of that features college kids, inbred twins, and a
fist-down-the-throat death scene.

"Probably the most beautifully shot and competently acted 'killer in
the woods' film from the early 1980s, Just Before Dawn is a must-see
for slasher fans...

A group of young men and women are traveling in a winnebago towards
the mountains. Warren (Gregg Henry) and his girl Connie (Deborah
Benson), Jonathan (Chris Lemmon) and his girlfriend Megan (Jamie Rose)
and Jonathan's brother Daniel (Ralph Seymour), drive past some locals
living in poverty. 'I wonder why there's so many twins around here?'
Daniel asks. Warren responds with an irreverent comment about
incest...

Roy McLean (George Kennedy), a forest ranger, lives in the area and
sees the them driving by his house. He comes out and demands to know
where the group is going. He's told they're going up to Silver Lake to
check out some land one of them has inherited. Roy gives them the old
'you've been warned' speech we've all come to expect in these
movies...

The killer is actually a set of twins!... The tree falls and the
grotesque twin comes after her with the machete. As he's about to
strike her, Roy shoots the killer...

Later, while packing up their stuff to leave... Connie has found the
inner strength to face danger. The surviving twin jumps out... Connie
musters up all the energy she can and...sticks her fist down the
killer's throat!"

The Terror Trap: Just Before Dawn
http://www.terrortrap.com/underratedslashers/justbeforedawn/

"Just Before Dawn" is available on DVD and VHS:

Amazon: Just Before Dawn DVD
http://www.amazon.com/gp/product/B0009G3BW4

Amazon: Just Before Dawn VHS
http://www.amazon.com/gp/product/B0001QYYRS

My Google search strategy:

Google Web Search: "just before dawn" inbred twins fist
://www.google.com/search?hl=en&q=%22just+before+dawn%22+inbred+twins+fist

I hope this is the right movie! If not, please request clarification;
I'll be glad to offer further assistance before you rate my answer.

Best regards,
pinkfreud

Outstanding!  That's it!

Thank you for the five stars and the tip!

~pinkfreud