Katahdin is the highest mountain in Maine and the northern terminus of the Appalachian Trail. It is located within Baxter State Park, a wilderness-managed area in which humans come second that some refer to as the 51st state. The mountain, being a mile above sea level, towers above the comparatively low Maine lakes and forests. Due to the northerly latitude, timberline is at about 3,500 feet.
Katahdin is most impressive from the south, a sheer-like granite fortress towering to the heights. It's shape is somewhat horseshoe-like with the open end heading northeasterly. There are 5 main peaks on the horseshoe, counterclockwise from the north they go--Howe Peak, Hamlin Peak, Baxter Peak (summit), South Peak and Pamola Peak. The most dominant and intimidating feature on Katahdin is the Knife Edge, an appropriately-named jagged arete only a few feet wide in places and a memorable traverse from South Peak to Pamola Peak. Katahdin is climbed frequently, being a popular destination because of its prestige.
Katahdin would appear to be volcanic in origin with it's cirques resembling craters, but it is actually granite that has been eroded away and carved by glaciers.
The first recorded climb occurred August 2-3, 1804 by Surveyor Charles Turner Jr. via the Hunt Spur. American author, Henry David Thoreau wrote of his 1846 climb of Ktaadn in "The Maine Woods."
Take Interstate 95 to the Millinocket-Mattawamkeag exit about 50 miles north of Bangor, ME. Proceed to Millinocket, following the signs, then turn right where the road "T's" by a high school onto Katahdin Ave. Go a couple blocks and take a left at the sign for Baxter State Park. Follow that about 16 miles to the park. From there, either take the Perimeter Road (to the left) or the Roaring Brook Road (to the right) to the trailhead for your ascent. In accordance with Governor Percival P. Baxter's wishes that the park be kept as wild as possible, the roads are gravel and used to be pretty rough.
The many routes to the summit all involve at least some scrambling from second to fourth class and come from three general directions, north, east and southwest. However there are several technical routes both rock and ice (refer to the Routes section for details). A campsite, Chimney Pond, sits within the cirque called the Great Basin. From this point, you can ascend the Cathedral Ridge Route (1.7 mi.) that runs up the salient ridge just west of Baxter Peak or the Saddle Trail (2.2 mi.) which is a bit more pedestrian. Or if you want to head up the Knife Edge (1.1 mi.) you would ascend the Dudley Trail to Pamola Peak (1.3 mi.). You can also head west from Chimney Pond to Hamlin Peak via the Hamlin Ridge Trail (2.2 mi.) if you want to hike the entire western side of the mountain to the summit.
You can also climb directly from the east via the Roaring Brook Campground on the Helon Taylor Trail (4.3 mi to summit). This takes you directly to Pamola Peak and the Knife Edge route to the summit and bypasses Chimney Pond.
From the southwest you can approach via Abol Campground or Katahdin Stream Campground which intersect and head up the Hunt Trail (the northernmost 5.5 miles of the AT). (5.2 mi total)
There is also the possibility of approaching from the far north via Trout Brook but this is more than a dayhike/climb.
Baxter State Park is tightly controlled and the amount of people allowed to enter each day is regulated. Come early if you desire to climb the mountain (even 6AM is at some times too late!) or camp in one of the campgrounds at Katahdin's base.
A fee is required to enter the park ($14). When inside Baxter, make sure you respect the rules specially designed for the well-being of the wild animals. The season runs roughly from May 15 to October 15; it used to be that outside these dates a complete set of required gear was required, however, the only required gear now is a working flashlight.
You are required to sign in at the campgrounds listing your names, route and time of departure/return before hiking in. You are also required to sign in at the hut at Chimney Pond when you arrive and depart there. This may seem like a hassle but the rangers I encountered there were not looking to cause problems, they were looking out for you, The night before we climbed, they were looking for someone who was late getting out and were genuinely concerned about that party.
Camping is permitted only by reservation in authorized campgrounds and campsites. It used to be that you had to start trying to get a campsite as early in the year as possible but it has changed so that now the earliest you can try to reserve a spot is 4 months ahead of time. If you are wishing to camp within the park , the best advice I can give is to request it then as they fill up quickly. Maine residents get preference too. During the summer the park is usually filled to capacity. (I requested reservations in January a few years ago to climb at the end of September and listed about 16 sites in order of preference. I was lucky to receive my 12th pick.) You can also try to make a reservation by phone if your desired date is within 10 days but don't count on getting a site.