3.4 mile (not including .75 miles on dirt road entry)
2800 feet elevation gain trip
The YDS Class 2 Northwest Ridge is clearly the most popular and direct way to the summit of Humpback Mountain. Most of this route is forested, however good views do break out the last 500 feet before you reach the summit. This popular in both summer in winter. In winter though, depending on road condition there is a possiblity that you will be adding up to 2 1/2 miles one way. Keep that in mind before attempting Humpback in winter.
VIA THE NW RIDGE ROUTE: From Exit 47 off of I-90 head south. Here is wher you want to reset your mileage and set it from the exit. At about 0.2 miles from Exit 4 you will hit a T in the road. Make a right near and head down the dirt road. Stay on the dirt road (good clearance for car) for about 1.3 miles (1.5 miles from Exit 47) until you see dirt road on your left. Make a left here and head up the road. At 1.5 miles from the previous intersection or 3.0 miles from Exit 47 you will hit a bend in the road and you with see jeep path that merges left. This is where you want to park your car.
The route starts as jeep road off of the dirt road mentioned in the getting there section. Take it roughly 3/4 of mile to a sand pit. The trail/bootpath starts off to the right of the sand pit. Keep your eye closely in this section. The first I was here I could not find the trail here. Follow the boot path (fairly easy to follow) up. It will rise steeply up the mountain. You will hit another dirt road roughly a 1/4 mile up. Continue going up the steep path. Though it is consistantly steep (well over 1300 feet a mile) the advantage is that the dirt here actually acts like a cushion and is very easy on the knees compared to other. You come accross a number of ledges at about 2 miles and break out on the barely YDS Class 2 boulder scramble. This boulder scrambles go for a couple hundred yards past a false summit, which look neat and at first looks like the true summit, and finally hits the true summit. A fit person or avid hiker can do this peak in about hour to an hour and a half up and an hour down.
This is basically a walk up, simple scramble. In winter snowshoes are required and an ice axe and crampons are advisable. As with all mountains in the I-90 region that are not established trails, use caution when rocks are wet or icy.
External Links Here is another good site on Humpback Mountain