I am guessing it is a combination of things in general
The temp this past weekend did not help at all, being able to watch it on line did not help the attendance at the track (I had it on the TV all weekend, there is a few things they can improve on but did a pretty darn good job with the online streaming), the other thing that has always bothered me with Eagle River is the amount of down time in between races and then you have the cost to actually get in. $75.00 for a weekend pass, $25.00 for Sat. and $30.00 for Sunday. I have been to the actual races twice (most recent about 5 years ago) and I live in Minneapolis area. So by the time I drive over there, get lodging for the weekend, food, admission and what not it adds up in a hurry. People where complaining about Hay Days increasing the admission price (there you get races, swap meet and LOTS of vendors). ER you get races and very few vendors).
Will I personally go back some year YES, still great races and a great venue.
just my $0.02