Well we run on some tracks here in Minnesota that do this and what I have changed really depends on what type of ruts/holes your experiencing.
Sharp small ruts - normally found on a track that hasn't been watered enough when repairing the hole left from last race! Usually in a clay based track.
Change to a tire that has less side bite. example Change from crossbrace to I-beams. If you can't change or don't want to change, take and cut the side lugs at a 45 degree angle to slide rather than catch the ruts. Take 1 -2 mm of droop away and or lower ride hieght 1-2 mm. You may want to go down in rear anti-squat if running 2 degrees go to 1 degree. If ruts are in high speed area then go up 5 wt in shock oils. You can try combo's of this to get what you want.
Huge holes that you lose you car in!!
If the track is more sand like or true loam then I would do the same with tires but increase droop to max and lighten the shock oils by 5 wt. Leave ride hieght same so drop setting helps. Most of all slow down in the corners and pick your line carefully. All anti-squat setting same as above. Hope this helps.