When I first started trail racing, we had mud like that. Usually it resulted in the wimpy guys in command calling the race off. A couple times we pushed through and I was one of 3 to make it. Yay for fenders and disc brakes.
Now in the East coast racing, almost 50 percent of the races are in rain and mud, but the mud is different. This stuff just kinda oozes and never sticks. Its fun.
Tip of the day: Armor-All the tires(careful not to hit the brake surface) and the mud won't stick as bad.
Ride it, break it, fixit, ride it...