Odd, in that they hadn't even left the restaurant in Roseburg until 9pm (if the report from the waitress was accurate) and it gets dark up there before 5pm this time of year. However on many maps (including mine) the road from I-5's exit 66/Merlin to Gold Beach is shown as just a regular secondary road, and the most direct (fastest) route from Roseburg. But that runs about 15 miles south of Glendale, and the connecting road from Glendale is shown as turning to dirt for a segment, but perhaps late at night in the dark of a car with just the overhead light the distinction might not be easily seen.
This is the map offered by the Lodge they were going to:
http://www.tututun.com/images/tututun_map.pdf