On the positive (or +) side, once you get as far as Trail Camp, your only problems after dark involve rodents. I did, however, run into two guys who went up the North Fork and spent Friday night at Upper Boy Scout, which is also above the tree line, and one of them had a really impressive collection of bites.
Yes, pack your repellant for the Portal, and keep it handy any time you're near water on your way up the Main Trail.
Phil
