The boat launch for Square Pond is spacious. Note the large culvert under West Shore Road at the right edge of this photo.
September 2, 2023
Location and Access to Square Pond
Where is Square Pond Located?
This 910-acre water body is found in the towns of Acton and Shapleigh, York County, Maine (see The Maine Atlas and Gazetteer map 2 B2). My goal this morning is trolling for trout on Square Pond.
Access and Boat Launch
The public access point is located along the western shore of the pond, off West Shore Road.
The entrance to the public launch is clearly marked by a blue sign by the road. However, beware that the launch does not face the pond, but is located by its outlet across the road.
Hence, boaters need to navigate through a large and wide culvert underneath West Shore Road to reach the pond itself.
The boat launch is spacious, has a huge parking area, and provides a convenient porter potty during the warm season.
I love the early morning “fog vibe” in late summer!
Square Pond Features, Stocking, Thermocline, Depth Profile, and Angling Rules
General Characteristics
Square Pond is a well-developed and busy lake located in a rural setting in northwestern York County.
Its one claim to fame is to have produced the state-record brown trout, namely a 23+ pound hog dredged up in 1996! It shows that this lake provides the habitat and forage needed to grow monster browns.
Annual Stocking
The State stocks this lake each fall with 500 yearling brown trout. Such a stocking density, i.e., about 1 trout every 2 acres, is the going rate for this species. Hence, it typically results in slow fishing.
Status of the Thermocline
I like targeting brown trout (as well as rainbow trout and splake) in summer because these salmonids are forced to “concentrate” around the thermocline, where two crucial conditions help ensure their survival: cool water and enough oxygen.
However, many lakes in southern and central Maine receive too much nutrient from their surrounding watersheds. This pollution causes excessive algal growth. The algae die, sink to the bottom, and decompose. This process uses up all the oxygen in the cold bottom water. That lack of oxygen prevents salmonids from swimming down there during the summer.
I use historical water quality data for Square Pond published by Lakes of Maine to identify the presence of a thermocline, its depth, and oxygen status. The information shows that the thermocline in late August-early September sits 23 ft. to 30 ft. below the surface. However, during that period, the oxygen levels in the lower half of the thermocline (i.e., 27 to 30 ft. down) can be too low to support brown trout. Hence, my target trolling depth this morning is between 23 ft. and 27 ft. down. The reason is that the water is oxygen-rich but too warm above 23 ft. and cool but oxygen poor below 27 ft.
Depth Profile
The pond has a mean and maximum depth of 20 ft and 44 ft, respectively. Click here for a depth map and more fisheries information.
Note that I print out the depth map when I do this type of targeted summer trolling. I then use a pen to outline the contour of my target depth, which in this case is 35+ ft. (i.e., trolling depth up to 27 ft. + a minimum of 8 extra feet of water.
That way, I know exactly what area(s) of a lake to target without wasting any time looking for it after I arrive. It is a simple but highly efficient approach.
Of course, this type of fishing requires a depth finder to help me stay over the correct depth.
Fishing Regulations
Summer fishing on Square Pond occurs under the general fishing laws applicable to the South Zone.
I am being pestered by white perch which are foraging right by the thermocline.
Trolling for Trout on Square Pond
Arrival and Conditions
I reach the Square Pond boat launch at 6 am. It is chilly (49°F) with lots of fog (click here, here, and here for other examples of this condition in late summer). The air temperature is expected to rise into the mid-60’s later in the morning. The surface water is a cool 70°F.
Technique for Trolling for Trout on Square Pond
I motor off at 6:15 am, pass through the culvert under the road, and immediately head towards the large island across the water where the deepest part of the lake is found.
I fish with two rods: my eight-weight fly fishing rod teamed up with lead core line fished almost 4.5 colors down, and a medium spinning rod teamed up with a portable downrigger to place the lures 25 ft. down. The lead core line fishes with three single-hook streamer flies, whereas the downrigger uses two Mooselook Thinfish spoons.
Results of Trolling for Trout on Square Pond
I get immediate action on both rods, but not of the kind I was hoping for: I am being pestered by white perch… They are aggressively foraging deep in the water column, and I hook six of them over the next 30 minutes. Even though I don’t care to catch these fish, the signal is loud and clear: my lures are not placed too deep. That is always a fear when doing this type of highly-targeted fishing.
The sun quickly rises, burns off the fog, and lights up the sky. The white perch bite soon stops and the action with it. I have been trolling for over an hour and decide to swap out my lures. I replace the two Mooselook Thinfish with two smaller Mooselook Wobbler spoons that provide a slimmer profile, but replace the smaller streamer flies with three bulkier double hook streamer flies. Gotta shake things up!
My downrigger rod moves violently 15 minutes later. I immediately set the hook and tussle with something bigger than a white perch. I am excited to see a 17” brown trout reach the surface. The fish gets measured, photographed, and quickly released to hopefully grow much bigger.
Granted, this creature breaks no state records…. However, it is always exciting when all my pre-fishing triangulations produce fruit.
This fish is shorter than hoped for but I am nonetheless glad to have caught my target species…
Hoping for Another Brown Trout …
I continue trolling with renewed hope around the 35+ ft deep bowl in front of the island. However, a large boat is pulling a water skier too close to my boat. I get the message…
It is time to move further north into the central portion of Square Pond where the water depth drops to between 30 and 35 ft. I place all my lures about 22 ft. Unfortunately, no ore brown trout appear over the next two hours. However, I hook two smallmouth bass, one of which is a fat and hard-fighting 17-incher, and another half a dozen white perch.
I call it good at 11:15 am, satisfied with my morning. Landing that one brown trout took a lot of work but past experience tells me that summer trolling for this species is always a slow affair 😊.
A nice by-catch. This fish fooled me into thinking I had hooked another brown trout until it breached the surface!
The outcome of trolling for trout on Square Pond: I caught one 17” brown trout, two smallmouth bass (largest = 17”), and a dozen white perch in 4 hours of trolling.
Was the information in this blog useful? I invite you to share your thoughts and opinions. Also, feel free to discuss your fishing experiences at this location.
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