Everyone else’s review is spot on. Lower Lena... no problem (very popular with a lot of chatty Cathy’s, small dogs, and families on the weekend) but Upper Lena is a bit challenging. Steep, trails overgrown with vegetation, often difficult to decipher or find, and random spots with heavy horse flies. I counted 15 downed trees that I either had to climb over, under, or around and I missed a switch back shortly after the lower Lena split and wandered off the trail. There was also another questionable creek crossing that was not clearly depicted. Needless to say I found Upper Lena and it was definitely worth it! Heard a mountain goat bleat in the distance around sunset but never saw one. A lot of deer activity at night near my tent (5 feet away/campsite #9) and mosquitoes were thick! Mosquito/insect repellent is a must!