It's a dirty time of year in urban Alaska. Here's how you can help clean up.

The trees are trying hard to open their leaves. Little bits of green grass are starting to poke up on brown lawns all across Southcentral Alaska.

But on top of that? Garbage and dog poop, all around the city of Anchorage.

Welcome to springtime in Alaska, when trash hidden under the snow during the long winter finally emerges, left on streets and sidewalks until someone picks it up.

That's where Citywide Cleanup Week comes in. It's been going on for 49 years, according to the Anchorage Chamber of Commerce, which organizes the effort each year.

In that time it has changed dramatically, according to ACC President Bruce Bustamante. It used to be a one-day event that culminated in a large celebration luncheon at Sullivan Arena.

But organizing the celebration took too much time away from the rest of the efforts, he said. With only one day to focus on cleanup, it was hard to coordinate schedules, so the chamber stretched it out to a week in order to get more people involved.

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In Anchorage, the week is bookended by free dump days on Saturday and May 6 — when residents can drop off loads at the Anchorage Regional Landfill in Eagle River at no cost.

Last year, 4,800 people dropped off trash over the two days, according to data from Anchorage's Solid Waste Services.

Bustamante, who has been a cleanup volunteer for about 17 years, said people keep coming back to help because they want to improve the community.

"The motivating part of it is to see how the city looks after you're done," Bustamante said. "We have friends and relatives coming to visit, we have tourists coming to town, but just for our own pride of ownership — just going to work each day or going out on the weekend, whether on trail system or walking around town. It's nice to see (Anchorage) cleaned up."

Baleen and shotguns

Craig Torrey, a fire inspector for the city, has been cleaning up sections of Anchorage for the last 15 years.

A self-described "Lone Ranger," Torrey fills dozens of bags each year before cleanup week even starts, usually in hard-to-clean-up places like the grassy shores of Westchester Lagoon.

He said the garbage revealed in snowmelt each year makes him feel "embarrassed as an Alaskan" and city resident. That's one of the main reasons he helps clean up every year.

He's found all kinds of things. One year he found an unopened, still-working Apple wireless keyboard. Another time he found a $100 bill. He said he used it to buy several grabber sticks to help collect trash, since he goes through a few each season.

Cherie Northon, executive director of Anchorage Waterways Council, organizes both the weeklong volunteer creek cleanup and "Scoop the Poop" Day, when people pick up feces left on the ground.

She said some of the weirdest things she's seen while working for council include a bowling ball, shotgun, giant truck tire, refrigerator and even a bearskin.

"You name it, we've found it," she said.

Bob Mitchell, 85, has been pitching in on cleanup for the last 19 years and organizes a group of Yale alumni that volunteers. The strangest thing he found in Chester Creek? A piece of whale baleen.

He and his wife, Mary Ellen, started cleaning up trash while taking walks along the Chester Creek greenbelt when they moved to Alaska in 1997. He said his desire to help with cleanup is simple.

"Growing up around streams, I like to see them clean," he said. "They are a great asset, a great resource and I just hate to see them being trashed."

The desire to pick up the city is one many longtime volunteers echo. Mary Fisher, director of Alaskans for Litter Prevention and Recycling, said Alaskans really come out when it comes time for cleanup.

"We are motivated to get outside and clean up from a long winter where we couldn't do anything like that for a long period of time. So we are concentrated in the springtime for getting stuff done," Fisher said.

"Not sure if (winter) has this effect of getting enthusiasm for cleanup, but I've never seen it anywhere else."

Southcentral cleanup events

'Scoop the Poop' Day

11 a.m.-3 p.m. Saturday at University Lake, Connor's Bog and South Anchorage Ballpark. Volunteers will receive supplies in order to clean up pet waste. Find details on Facebook or anchoragecreeks.org.

Anchorage Waterways Council Creek Cleanup

May 11-15, at various creek locations. See anchoragecreeks.org for details.

Free dump days

Drop off loads for free on Saturday and May 6, from 8 a.m. to 5 p.m., at the Anchorage Regional Landfill, 1550 E. Eagle River Loop Road. Trash must be less than 1,000 pounds and be smaller than a standard pickup truck bed. No oversize trailers or U-Haul-type vehicles allowed. The Central Transfer Station in Anchorage will be closed. See muni.org for details.

Anchorage citywide trash pickup

Pick up bright orange city cleanup bags at Anchorage and Eagle River Fred Meyer customer service counters. The bags can be dropped off free of charge at the Central Transfer Facility, 1111 E. 56th Ave., May 1 through May 5. Do not leave bags on the side of the road; they must be disposed of by the organizer. Cleanup teams can register with the Anchorage Chamber of Commerce to arrange for additional pickup bags. See anchoragechamber.org for details.

City of Wasilla Cleanup Days, May 1-6

Pickup bags are available at the Wasilla City Hall Public Works Department, the Greater Wasilla Chamber of Commerce, Menard Sports Center and Dorothy Page Museum. Bags can be dropped off at a dumpster at the Iditapark parking lot from noon to 7 p.m. each day. A volunteer celebration is set for 2 p.m. May 6 at the Iditapark red pavilion. See cityofwasilla.com for more information.