Put on cross tires if you want to ride the length of it. The gravel sections are actually some of the nicest portions of the trail. If you spend you're entire time in those sections worrying about taking a spill it will certainly spoil the experience. There is at least one very short, but steep, bit of single track (something like a 100', easily walked).
I did it last year on my fully loaded touring bike with 1.25" tires. Had a blast, even found some mushrooms to forage for the night's stew pot that were right on the trailside.