I’ve written a few posts covering the urban fishing opportunities around Denver; Lambertson Ponds and Mann-Nyholt Lake. I’ve also covered a facility whose sole purpose is to supply the public with excellent fishing; St. Vrain State Park. This week I’m going to share a place that perfectly combines the convenience of urban fishing with the excellent fishing of a state park; Thornton Gravel Lakes Fishing Facility.
This facility, as its name implies, exists for the purpose of fishing. Nestled right next to the South Platte River in Thornton, the lakes are maintained by the city of Thornton and stocked, with both catchable trout and warmwater species, by Colorado Parks and Wildlife. The end result is excellent fishing just 10 miles from downtown Denver. Click HERE for directions.
There are two lakes which are open to the public within this facility; Gravel Lake #2 and #3. Lake #2 is the lake you see as you first pull into the parking lot. Lake #3 is only accessible on foot and requires a short ½ mile walk down a gravel path to get to it. Both lakes contain an aeration system which keeps the water oxygenated and algae growth at bay. Subsequently, the fish have an excellent environment to live in and they thrive. The smaller species (sunfish and perch) are plentiful and the predatory fish can get quite large due to this abundant food source.
The lakes hold quite a variety of fish species. Colorado Parks and Wildlife’s website claims the lakes contain; rainbow trout, carp, largemouth bass, smallmouth bass, bluegill, crappie, perch, channel catfish, and walleye. I have personally seen or caught all of those species with the exception of the catfish and the walleye. I don’t doubt that catfish are present, but the walleye I might have to see to believe.
You won’t find solitude here but you can have quite a day on the water if you know what you’re doing. Pretty much every person you see fishing will be using worms or Powerbait. This technique will land them plenty of the stocked rainbows and the occasional catfish, carp, or bass, but here the fly fisherman has the advantage. The larger fish in these lakes don’t see a lot of flies and if you find a good spot you will do quite well.
The perch and bluegill can be found in abundance near the shore and under the fishing piers on lake #2. They can be taken easily using a dry dropper rig, just be sure to use small flies. Enormous carp, some pushing 40″, can be seen cruising the lake and can be landed using crawfish patters, nymphs, or San Juan worms. The bass are my favorite target and can be found typically near the fishing piers or along rocky drop-offs like this one:
A top-water bass popper fly will get you some exciting action, but streamer fishing will land you the most fish. The setup I have found most productive is a wooly bugger with a nymph pattern or a scud trailed about a foot behind. For the nymph pattern I have had success with several different patterns including; zug bugs, copper johns, and emerger patterns. And don’t think that the nymph trailer is just a gimmick to land a few bluegill when the fishing is slow, I’ve landed several smallmouth over 10” on that nymph trailer. Bass have a tendency to strike between retrievals, when the fly is relatively motionless in the water, so a slow retrieve of the streamer with pauses is preferable. Let the fly sink between the rocks but be careful not to get snagged. The bass tend to hide in the crevices between the rocks and dart out to attack passing food sources.
Be sure to have some stronger leaders and tippet if you go after the bass and carp. These species can get quite large and are strong fighters. Purchase some bass leaders if you want, but if you have 3x, 4x or larger leaders in your supplies they will work as well. 3x, 4x and larger tippet is also advised for the nymph trailer. The thicker line has not limited my strikes and it has held up quite well against the rocks and the runs of some nice bass.
In conclusion, Thornton Gravel Lakes are a wonderful urban fishery and easily accessible to the populous of the Denver metro area. You can catch a bunch of different species in one spot and most of them will go after the same flies. For my money the smallmouth bass fishing is the best, but the rainbows are plentiful and the carp are huge as well. The lakes are open all week from 6am until 11pm. However, they are closed during the winter so don’t bother heading here before March 15th or later than November 1st. Streamers and nymphs seem to work best, but poppers, dry flies, and some nymph rigs can also be effective. So the next time it’s storming up in the mountains but you still want to wet a line, check these lakes out, you won’t be disappointed. Until next time, happy fishing!
– A. Egli