The highland cattle ranch is called the MM Ranch. It's located at 57242 Parkersburg Rd. Bandon, OR 97411. According to mapquest, it is about 9 miles from that point to the closest road alongside the ocean (can't remember the name of that road--was late last night). No clue whether or not it was in operation in the 80's but I'm questioning whether it was or not.
The important thing is that it isn't what you saw and that rules out a highland cow.