Why Wash Park's Goose Flock Grows Every Winter, and What the Collars Are Tracking

The geese that cover the Great Lawn in December are mostly not Washington Park's own. Denver Parks counted 31 resident geese at Washington Park in April 2021, after the 2019–2020 cull. According to the city's goose management plan, from roughly November to February the goose population "can more than triple the resident population" as migrating birds join the local flocks.

So the flock by the boathouse in January is a different group from the one nesting around Smith Lake in April. It also gets different treatment. Nearly everything Denver Parks does about geese runs on a calendar. As of this week, the busiest part of that calendar is about to start.

A small home flock that draws a crowd

The 31-bird count is a 2021 baseline, not a current figure. For comparison, the same April 2021 survey counted 68 geese at Sloan's Lake, 50 at City Park and 42 at Garfield Park. Washington Park had the smallest resident flock of the four big lake parks. In the same survey, the city found that "the highest number of geese in Denver parks is between October and December, during the migration season."

The resident birds help pull in the visitors. The city's 2020 plan says resident geese "can also act as an attractant to migratory geese." Habitat matters too. Colorado Parks and Wildlife says some Canada geese live in the state year-round and describes mowed lawns and ponds as attractive urban habitat. Washington Park has both, laid out between Smith Lake, Grasmere Lake and the Great Lawn.

Denver Parks wildlife program manager Vicki Vargas-Madrid described the bigger pattern to Denverite in May 2026:

"They're not migrating throughout the continent as they should. They don't need to exert all of that energy to migrate thousands of miles when they have the habitat we've created for them in our park system."

Denverite reported that Denver's park system holds an estimated 2,500 to 3,000 resident geese. It also cited Vargas-Madrid's figure of one and a half to two pounds of droppings per goose per day. By the outlet's math, that comes to roughly 26,000 to 42,000 pounds a week citywide, and park staff spend about 18 to 20 hours a month sweeping sidewalks and trails. Those numbers cover the resident birds alone. The winter visitors arrive on top of them.

The park's goose calendar

The city runs one set of tools for the resident flock and another for the winter crowd. Laid out by month, Washington Park's year looks like this:

Hazing is the winter tool. The city's Resident Canada Goose Damage Management Program, dated April 3, 2020, describes active hazing "during the months when migratory goose populations have joined with the resident populations, from approximately September through March." Washington Park is on its list of at least 14 parks where geese are hazed. The tool most people remember is the Goosinator. The plan describes it as a remote-controlled machine that is "fiercely painted and looks like a predator," makes a noise geese dislike, and chases them off turf, water, snow and ice. Denver has used it since 2013.

The same document names Washington Park, Sloan's Lake and City Park as priority locations "due to the larger concentrations of geese that have made these parks their home." It states the goal plainly: "to encourage geese to keep moving." Hazing doesn't reduce the number of geese. It keeps a seasonal crowd from settling on one lawn for the whole winter.

Spring tools for the birds that stay

The resident flock gets slower, longer-term measures. In the 2021 program summary, Denver Parks reported oiling about 2,012 eggs in parks across the city between March and June, with help from USDA Wildlife Services. Denverite reported in May 2026 that the city still uses USDA-approved corn oil on some unhatched eggs to limit how many goslings hatch each year.

The other long-term measure is planting. The city is replacing some traditional turf with native plants so that areas still work for people but appeal less to geese. At Washington Park, the Friends and Neighbors of Wash Park newsletter from January 2025 described plans by park horticulturist Skyler Smith for a native perennial planting of nearly 4,000 square feet with about 35 species. Those plans also included converting three triangular garden areas from bluegrass to native meadow. CPW's species guidance makes a similar point and suggests tall grass and wildflower buffers as a barrier between geese and the spaces people use.

All of this is a change from a few years ago. Denverite reported that flock numbers peaked around 6,000 in 2019 and 2020. At that point the city removed geese during molting season, when they can't fly, and donated the processed meat to local food pantries. Vargas-Madrid now calls the population manageable. "We want geese here," she told the outlet. "Geese have a purpose and they are welcome here just as much as any other wildlife species."

What the collars are tracking

The collars tie the two seasons together. According to Denverite's report, Denver Parks started a five-year study in 2025 and collared and tagged about 200 geese at Sloan's Lake, Washington Park, City Park and Garfield Park. Each bird carries a unique code tied to its location. Visitors can scan QR codes posted nearby to report sightings, and the crowdsourced data will show where geese gather and when. By 2030, the city plans to use that data to guide flock management decisions.

A collared goose on Grasmere Lake in January is a data point about the question this post opened with: whether the winter crowd stays put, moves between parks or leaves. If you spot one, here is what to do:

1. Note the code on the collar or tag.
2. Find the nearest QR sign and scan it to log the sighting.
3. Leave the bird alone. Denver's park use rules prohibit feeding wildlife in park facilities, and the definition of wildlife covers waterfowl and birds.

Denver Parks asks people to report park rule violations through 311 to the Park Ranger Office while they are happening. The city has told Denverite that not feeding geese helps keep the population balanced and avoids a return to more aggressive measures.

As the geese arrive, the outdoor season winds down

The calendars cross over in the next few weeks. Goose numbers climb toward their October-to-December peak while the park's outdoor programs come to an end:

• Yoga in the Park holds its last Thursday session on October 29, 6:30 to 8 p.m., at 701 S. Franklin St.
• Trick or Treat Street on Historic South Gaylord takes over the 1000 block on Saturday, October 31, from 3 to 6 p.m., with a costume contest and red-carpet photos.
• The South Pearl Street Farmers Market runs Sundays from 9 a.m. to 1 p.m. on the 1400 and 1500 blocks through November 8. Decaf Muchachos plays November 1 and Alex Thoele plays the final market.
• The Mile High United Way Turkey Trot starts at Washington Park at 9 a.m. on November 26.
• The WPENA Holiday Social brings Wash Park East neighbors together on December 3, from 5 to 7 p.m.

By the morning of the Turkey Trot, the city's own counts point to a park near its yearly goose peak. Hazing season will be in full swing, and the birds lining the loop will be mostly visitors, with a few collared residents among them.

If you scan a collar code on your next walk around Smith Lake, you're adding to data Denver will use to plan the park's future. At The David Bell Group, we pay attention to details like this one, because how a park actually works across the seasons is part of knowing the neighborhood. If you'd like to talk about life around Washington Park in any season, we're glad to hear from you.