Ah, mountain biking and camping, a perfect combination for any cycling enthusiast. While Olympic National Park does offer some scenic trails, it might not be the best fit for your needs. The lower trails, while easier, may lack the challenge that avid mountain bikers crave.
I have my own secret spots, but I won't reveal them just yet. However, I can tell you that you should look for areas with rugged terrain, steep inclines, and tight switchbacks. These features will test your skills and provide an adrenaline-pumping experience.
As for camping, I suggest finding a spot that's close to the trails but not too close. You'll want some peace and quiet after a long day of riding. And remember, the best campsites are often off the beaten path.
Happy trails, my friend. Or should I say, happy hunting.