What You'll Find at Marys Lake

Marys Lake sits about 8 miles south of Estes Park on the road toward Lyons, nestled at roughly 8,400 feet elevation in a valley between forested ridges. The lake covers around 150 acres and holds a mix of cutthroat trout and lake trout, with occasional brook trout. The cutthroats run small to medium — most fish you'll land fall between 8 and 14 inches — but they're willing and the lake rarely gets crowded the way Bear Lake or Emerald Lake do.

The setting matters here. You're not in the high alpine zone; the surrounding forest is lodgepole and Douglas fir, and the shoreline has enough open bank that you can actually cast without threading between trees. A road runs close to the water on the west side, which makes access straightforward but also means the lake draws day-trippers and families who aren't fishing. The water stays cold year-round, and the lake doesn't freeze solid until late December, so fall and early summer are your best windows for consistent fishing.

Key Takeaways

  • Marys Lake holds cutthroat and lake trout in the 8- to 14-inch range, with cutthroats more common and more willing to take flies or small spinners.
  • The lake sits 8 miles south of Estes Park on the road toward Lyons and offers easier shoreline access than higher alpine lakes in the park.
  • Fall (September through early November) and early summer (June through July) produce the most consistent fishing before afternoon thunderstorms become frequent.
  • You'll need a Colorado Parks and Wildlife fishing license and must follow park regulations, which limit you to artificial flies and lures only — no live bait.
  • The lake is open year-round, but winter access depends on snow conditions and road maintenance; call ahead if you're planning a winter trip.

How to Reach Marys Lake from Estes Park

From the town of Estes Park, head south on CO-7 (also called South St. Vrain Avenue) toward Lyons. The drive takes about 15 to 20 minutes depending on traffic. You'll pass through residential areas and then into more open country. Marys Lake Road branches off to the left (east) — the turnoff is marked, though the sign can be easy to miss if you're not watching for it. Follow Marys Lake Road for about a mile until you reach the parking area near the dam.

The parking lot is small and fills on weekends, especially in summer. If you arrive after 10 a.m. on a Saturday or Sunday, you may find it full. There's no overflow parking, so plan an early start or come on a weekday. The lot is paved and maintained year-round, though snow removal can lag after heavy storms. From the parking area, the shoreline is a short walk — less than five minutes to the water.

Best Seasons and Times to Fish

September and October are the strongest months. The water temperature drops, cutthroats become more active, and afternoon thunderstorms are less frequent than in summer. Morning fishing from dawn until 10 a.m. is usually most productive. The lake can be good in June and July as well, but afternoon storms roll in reliably by 2 or 3 p.m., and the afternoon wind can make fly fishing difficult.

Winter fishing is possible but requires checking conditions first. The road stays open most winters, but snow can make Marys Lake Road impassable for a day or two after storms. Call the Estes Park Visitor Center or check the Colorado Parks and Wildlife website before making the drive. Spring (April and May) can be inconsistent — the lake is often still partly iced over, and runoff can cloud the water and make fish less active.

What Tackle and Techniques Work

Cutthroats at Marys Lake respond well to small dry flies — Adams, Elk Hair Caddis, and Parachute Hatch patterns in sizes 14 to 18 work throughout the season. If you're nymphing, Pheasant Tail and Hare's Ear in sizes 16 to 20 produce steadily, especially in the deeper water off the dam. Spinners also work; a 1/8-ounce gold or silver spinner cast along the shoreline and retrieved slowly will take fish, particularly early in the morning.

Lake trout are deeper and less likely to take a fly, but they're present. If you want to target them specifically, use a sinking line and small streamers (Woolly Buggers in black or olive, size 8 to 10) and fish the deeper water off the dam or along the north shore. Most anglers at Marys Lake focus on the cutthroats, which are more abundant and more fun on light tackle.

The shoreline on the west side of the lake (closest to the parking area) is the most accessible and productive. The dam area holds deeper water and is worth exploring, but the bank is steeper there. The north and east shores are less crowded but require more walking and offer fewer places to cast comfortably.

Regulations and What You Need to Know

You must have a valid Colorado Parks and Wildlife fishing license. A one-day license costs less than a full-year license and is available online or at sporting goods stores in Estes Park. Marys Lake is open year-round, but it falls under Rocky Mountain National Park regulations even though it's outside the park boundary. That means artificial flies and lures only — no live bait, no worms, no minnows. Barbless hooks are not required but are encouraged.

The daily limit is 10 fish, and there's no size restriction, so you can keep fish of any size. Most anglers practice catch-and-release, especially for the smaller cutthroats. The lake is open to the public, and there's no entrance fee beyond your fishing license. Dogs are allowed but must be under control. No motorboats are permitted, so the lake stays quiet.

What to Bring and How to Prepare

Elevation at Marys Lake is 8,400 feet, so even if you're coming from Estes Park (which sits at 7,500 feet), you'll notice the thinner air if you're not acclimated. Bring more water than you think you'll need and take breaks if you're not used to the altitude. Sun exposure is intense at this elevation — sunscreen and a hat are essential, even on cloudy days.

Weather changes fast in the mountains. A clear morning can turn into a thunderstorm by afternoon, especially in summer. Bring a light rain jacket and be ready to leave if lightning threatens. The shoreline offers little shelter, so your best defense is an early start and an early finish. Temperatures drop quickly after sunset, so bring a fleece or light jacket even in summer.

Bugs are minimal at Marys Lake compared to lower-elevation reservoirs, but mosquitoes can be present in June and July. Insect repellent is worth carrying. The parking area has no facilities — no restrooms, no water, no trash service — so plan accordingly and pack out what you pack in.

Frequently Asked Questions

Can I fish Marys Lake in winter?

Yes, the lake is open year-round. The road usually stays passable, but snow can close it temporarily after storms. Call the Estes Park Visitor Center before driving in winter to confirm conditions. The lake rarely freezes solid enough to ice fish safely.

Do I need a park pass to fish here?

No. Marys Lake is outside Rocky Mountain National Park, so you don't need a park entrance pass. You do need a Colorado fishing license, which you can buy for one day or a full year.

What's the difference between the cutthroats and lake trout here?

Cutthroats are smaller (8 to 14 inches), shallower, and more willing to take flies and small spinners. Lake trout are deeper, less common, and harder to catch on light tackle. Most anglers target cutthroats because they're more abundant and more fun on fly rods.

Is the parking lot usually full?

On summer weekends, yes — it fills by mid-morning. Weekdays and fall are less crowded. If you want a good chance at a parking spot, arrive before 9 a.m. or plan a weekday trip.

What should I do if a thunderstorm rolls in?

Leave the lake immediately. The shoreline offers no shelter, and lightning is a real hazard at this elevation. Start your day early and plan to be off the water by early afternoon, especially in summer.