From the source of the West Branch to its confluence with the East Branch in Medway, is approximately 200 miles. The West Branch drains approximately 2,000 sq. miles in Somerset, Piscataquis, and Penobscot counties. Lakes such as Seboomook, Chesuncook and Pemadumcook are located along its course. The West Branch is a high quality large volume white water river which contains significant Class V stretches (below Rip). It also contains five of the forty rapids identified by the Maine Critical Areas Program as having statewide significance. All are class IV or V with the Cribworks being one of Maines most turbulent rapids.
The North and South branch of the Penobscot feed Seboomook Lake. Below Seboomook you find the beginning of what is commonly known as the West Branch. Seboomook Lake levels are regulated by Seboomook Dam (see Maine Atlas, map 49) as is the 48 mile flow from Seboomook Lake to Chesuncook Lake. Roll dams is located about three miles downstream from Seboomook dam and is a series of upright tooth ledges (mostly green slate) which drop into quick current and flat water. This type of water continues thru Penobscot Farm, past Hannibals Crossing, around Big Island, past Ragmuff Stream and into Chesuncook Lake. The only section that has rapids is that section around Big Island. That however shouldn't lead you to think this area is fishless. Hannibals Crossing is a site which provides canoe or hand carry access, and Penobscot Farm has a boat launch. These places are worth going to, but they are a long way from anywhere. Not a day trip go prepared to stay or you wont have time to enjoy the fishing. Dont forget to check out Lobster Stream, if not for fish look for feeding Moose.
The section from Rip dam to Abol bridge is the best known part of the river and it runs for approximately 11.5 miles, and drops about 310 feet in elevation. Great Northern Paper Companys (Bowater) major access road (the Golden Road) runs along the south shore of much of this stretch and provides easy access. This section of river averages about 200 feet wide, and offers some of the states best fishing. You will find the best fishing from about Memorial Day to mid July. Look for a flow of 2,500 to 3,000 cfs.
Ripogenus dam (Rip dam) was built in 1920 and forms Chesuncook & Ripogenus Lakes. It spans a 695 foot wide gorge and is 73 feet high. The gorge below the dam is steep walled (240' high in some areas) and runs for about 1 mile. The original purpose of Rip dam was to control flow in the river for the movement of pulp. All of that stopped in 1972 when the use of the river for pulp drives was banned. In the early 1950's a tunnel was bored in the rock from the dam to McKay Station. There, after providing power by driving turbines the tunneled water is released back into the river through penstocks. This water is cool year round and in the spring has the added incitement of containing many dead and stunned smelt, floating smelt patterns can bring good action.
The distance from the Big Eddy to Ambajejus Lake is about 25 miles. You will find every kind of water here from flatwater, to rapids, to heavy rapids, to falls. This is no place for the inexperienced fisherman or canoeist. Those who wade be careful and mindful of where you will be swept by the river should you take a dunking. Those who canoe BEWARE. Even if you plan on just paddling out and dropping anchor, fishing and returning directly to your launch site, BEWARE. Water flows change and sometimes change rapidly - this river can take you and your anchor with it.
Below the gorge fishing can be had at limited spot accessible by hiking and climbing a little. You will find sites like the Little Eddy and other spots not commonly known. These sites are only known to those who have explored the easier accessed sites and then exerted the effort needed to find the little known sites. Most of these sites are worth finding if not for the fishing just to be able to say you found them.
At Prays campground you can launch, there is no charge to do so. However, if you wish to use the facilities there is a small fee. This puts you smack in the middle of what is called the Big Eddy. Good fishing here. Yes, you can wade, but the water gets deep fast and the current is strong. For about a mile below you will find fast but, reasonable water, providing it isnt spring freshet or just after a big rain. This water brings you into Little Ambejackmockamus Falls; if you can get back upstream go. This is just the beginning of what becomes Class III to IV water. You can get out on the right hand bank and do some fishing and scouting, just a little looking around should convince you that upstream is the best way to go. That or perhaps you have arranged a shuttle. Where are the take out and put ins for this shuttle, you ask? If you dont know you shouldn't be on the water rather you should be wading and learning what this river is saving for you. This is a lot of water you cant fish it once or twice and know it, plan on coming back and adding to your knowledge.
Little Ambejackmockamus flows into Big Ambejackmockamus which flows into Horserace Rapids. There are many spots to fish here. Big water, fast water, hard wading and accessible with a little hiking. Bring a wading staff and plan on picking pockets and fishing weighted flies.
Horserace Rapids bring you into Nesowadnehunk Dead Water. You can launch a boat here. Early action can be had on this two mile stretch know as Sourdnahunk Deadwater. This section starts at Horserace Falls and extends to the head of Sourdnahunk Falls. This stretch is nowhere as productive during the warmer months; yet it is never to be ignored. Keep in mind that the Deadwater ends with a waterfall. The section of water which is both the end of the Horserace and start of the Deadwater bears attention.
Sourdnahunk Falls provides good fishing, but is so easily accessed that it is usually crowded and often suffering from heavy pressure. A hundred yards below the falls the river begins another series of Class II & III water. Good fishing can be had here while just above you people are standing or sitting waiting for a chance to get to "that spot." These rapids go on for about a quarter of a mile and turn into fairly flat water known as Abol Deadwater. Good fishing can be had here but access again requires hiking or a trip upriver from Abol which has no boat launch. You can get a boat in the water but it takes some work. A hiking day trip from Abol Bridge to the falls and back is a good round trip. The trip is a lot more comfortable if you are wearing a pair of Breathable Waders. (take my word for it, I know from experience!)
The Abol Bridge Pool is productive. Two streams enter the river at this point They are the Abol and the Katahdin. Later in the season they create one of the most natural attractions a river can have. Moving water from a cool source.
Landlocked Salmon are the most sought after fish in the West Branch. There appears to be a large movement of Landlocks in the spring up river from Pemadumcook Lake, and by June the river population of Landlocks greatly exceeds the winter holdover population. One of the things that may trigger this movement is Smelt. Large schools of smelt move from Ambajejus Lake into the river during the spring spawning season. The run is one of the longest and heaviest in the state. It has been known to last as long as three weeks.
More Smelt come into the river from the other end along with the water discharged from Chesuncook Lake. Those that survive the tunnel, turbine and penstock add to the river population of Smelt which is one of the things that make this section of the West Branch unique. Most Landlocked Salmon rivers in the state cannot boast such a ideal source of food. Those other rivers in the state that support Smelt certainly cannot match the numbers found in this section of the West Branch.