What to expect at Willow Creek Reservoir

Willow Creek Reservoir sits in the high country west of Granby, Colorado, at roughly 8,000 feet elevation. It's a smaller impoundment—about 70 surface acres when full—that holds cold water year-round and produces solid populations of rainbow and cutthroat trout. The reservoir is accessible by car, has a developed boat launch and picnic area, and draws a steady mix of anglers and families, especially on weekends during summer.

The water stays cold enough that trout remain active even in July and August, which makes it different from many lower-elevation reservoirs in the region that warm up and slow down. Willow Creek also has less pressure than some of the better-known waters nearby, so you can often find fish without fighting crowds. The drawback is that the reservoir fluctuates with irrigation demand—water levels can drop significantly by late summer—so access and fishing conditions change through the season.

Key Takeaways

  • Willow Creek holds rainbow and cutthroat trout in cold water that stays fishable through summer, unlike lower reservoirs in the region.
  • The boat launch and picnic area are developed and free to use, though you'll need a Colorado Parks and Wildlife fishing license.
  • Water levels drop as the season progresses due to irrigation, so plan your trip early in the season for the best access and highest water.
  • Trolling with small spinners and spoons works well in spring and early summer; switch to nymphs and small dry flies near the inlet as water warms.

How to reach Willow Creek Reservoir

From Granby, take US Highway 34 west toward Grand Lake. About 8 miles out of town, turn north on County Road 6 (also signed as the road to Willow Creek Reservoir). Follow it roughly 5 miles to the reservoir. The road is paved for most of the distance and passable year-round, though winter snow can make it rough. There's no fee to park or launch a boat.

The boat launch is on the south shore and has a gravel ramp suitable for small to medium boats. If you don't have a boat, you can fish from shore along the dam and around the inlet area. Cell service is spotty, so download maps or directions before you leave Granby.

Trout species and seasonal patterns

Willow Creek holds both rainbow trout and cutthroat trout. The rainbows tend to be more aggressive and grow to 12 to 16 inches on average; cutthroats are present but less numerous. The reservoir is stocked periodically by Colorado Parks and Wildlife, though natural reproduction also occurs in the inlet stream.

Spring (May through early June) is when the reservoir is fullest and trout are most active after winter. Trolling with small spinners—size 1 or 2 Mepps or Panther Martins—works well in 15 to 30 feet of water. Early summer (late June through July) shifts the bite toward the inlet, where cooler water and food bring fish shallow. By August, water levels have often dropped and the reservoir narrows; focus on deeper holes and the channel near the dam. Fall (September through October) brings another active period as water cools again.

Tackle and technique for Willow Creek

A light spinning rod (5 to 6 feet, 4 to 6 pound test) covers most situations at Willow Creek. If you're trolling from a boat, small spoons like Kastmasters or Krocodiles in silver or gold work well. From shore or in shallow water, small spinners and inline spinners (size 0 to 2) are effective. Bring a selection because trout can be picky about color—try silver, gold, and copper first.

Fly anglers should bring a 4 or 5-weight rod with a floating line and a sinking tip. Small nymphs (size 14 to 18 Hare's Ears, Pheasant Tails, and Copper Johns) work near the inlet and along drop-offs. Dry flies are less consistent but small Adams and Pale Morning Duns can produce in late evening during summer. The water is clear, so use a 4 to 5-foot leader and tippet in the 4X to 5X range.

When water levels drop and access changes

Willow Creek Reservoir is managed for irrigation, which means water levels begin dropping in July and can fall 15 to 20 feet by September. A lower reservoir concentrates fish but also shrinks the fishable area. The boat launch may become unusable if the water drops too far, though shore fishing near the dam usually remains possible.

Call the Granby Parks and Recreation office or check the Colorado Parks and Wildlife website before a trip in late summer to confirm current water levels and launch conditions. If you're planning a boat trip, go early in the season. If you're fishing from shore, late summer can actually be productive because fish are compressed into a smaller space.

Regulations and licensing

You need a valid Colorado Parks and Wildlife fishing license to fish Willow Creek. You can purchase a one-day license, a five-day license, or an annual license through the CPW website or at sporting goods stores in Granby. Trout limits are typically two fish per day with a 10-inch minimum size, but check the current regulations on the CPW website because rules can change.

The reservoir is open year-round, though winter access depends on snow conditions on County Road 6. No motors are restricted, but the reservoir is small enough that jet skis and high-speed boats are uncommon. Camping is not allowed at the reservoir itself, but Granby and the surrounding area have several campgrounds and lodging options.

Nearby water and alternative options

If Willow Creek is too crowded or water levels are too low, Shadow Mountain Reservoir (also near Granby) offers similar trout fishing with a larger surface area. Lake Granby itself is bigger and warmer, better for walleye and pike than trout. The Colorado River runs through the area and has good cutthroat fishing in sections, though it requires wading and is more technical than reservoir fishing.

Grand Lake, about 15 miles north, is the largest water in the region and holds lake trout and mackinaw along with rainbows. It's more crowded and the fish are often deeper, but it's worth a day trip if you want to explore beyond Willow Creek.

Frequently Asked Questions

Can I fish Willow Creek in winter?

Yes, the reservoir is open year-round. Winter fishing can be good because trout remain active in cold water, but access depends on snow conditions on County Road 6. Call ahead to confirm the road is passable before making the drive from Granby.

What's the best time of year to visit?

Late May through June offers the fullest water and most active fish. July and August are good for shore fishing near the inlet, but water levels drop and boat access becomes limited. September and October bring cooler water and another active period, though the reservoir is smaller.

Do I need a boat to fish Willow Creek?

No. Shore fishing along the dam and around the inlet is productive, especially in summer and fall. A boat gives you access to deeper water and more area, but you can catch trout from land without one.

What size trout can I expect?

Most rainbows run 10 to 16 inches, with occasional fish to 18 inches. Cutthroats are usually smaller. The reservoir is stocked regularly, so size and numbers vary by year and season.

Is there a fee to fish or launch a boat?

No fee to fish or use the boat launch. You only need a Colorado Parks and Wildlife fishing license, which you can purchase for one day, five days, or a full year.