I did it at 36. The hardest part is the suicidal river run. It's actually rather simple you just have to have some luck on which way the vultures are looking. The first time I tried it, I had agro'd one and taken some damage, and instead of stopping to heal when it lost agro.. I kept going and agro'd a second + a eft. (the efts chase you a little farther but they rarely range attack and are easy to out run.) Ended up dying to 2 ranged attacks from the second bird.

My second attempt to run through, I only agro'd 2 efts (which did no damage) all the birds were looking away and I ran behind them. Vultures = Sight. Run behind or to the side and they won't agro.

Get passed the water and you're in the clear.