Lost something on Mercer Island? Report it once and let us handle the rest.
File one report and we notify the Mercer Island Police Department, check with local businesses and public spaces, and keep your report actively searching for matches across community channels.
What did you lose?
If there isn’t an adequate suggestion, select “Other – My item isn’t listed” and enter the item’s category. You can provide details later.
Publishing your report is free and your details stay private. The assisted search is a separate paid service, described in the Terms.
Recent activity
Washington : the owner's claim window is 60 days, shorter than in most states, and a finder must report the find within 7 days. (RCW 63.21)
Reported in Mercer Island
- WalletAugust 4
- UmbrellaAugust 3
- SunglassesAugust 1
Across the United States
- Wrislet clutch gray/silver bag with documents · Chicago, IL, October 8
- Ring TM on top · Greensboro, NC, October 8
- Keys · Sarasota, FL, October 8
- Keys · Brookline, MA, October 7
- Camera · Monterey, CA, October 7
Local contact details reviewed on October 7, 2026.
How ReportLost Works
You tell us what you lost
Describe your item, where you lost it on Mercer Island, and when. We gather the details needed to get results.
We route your report to the right places
Your report goes to the Mercer Island Police Department, relevant businesses, transit lost and found services, and active community groups all at once. No more making ten calls yourself.
Your report keeps searching for you
For your entire search period, your report stays active and cross-checks new found posts, community messages, and local marketplace listings. You get an alert the moment a credible match appears, so you don't have to check Facebook and Nextdoor every single day.
Where to report a lost item
These are the main channels on Mercer Island. ReportLost handles notifying them for you, but you can also reach out directly.
Mercer Island Police Department
The Police Department maintains lost and found records and can file reports for items lost across the island. We tell you which department handles your specific loss location and what information they'll need.
City of Mercer Island
City Hall can point you toward the right department for items lost on public property or in city buildings. We generate the exact information you'll need when you contact them.
Island Transit Lost & Found
If you lost your item on an Island Transit bus, their lost and found team can search for it. We point you to the right transit service for your specific route.
Local businesses and public spaces
Lost something at a restaurant, store, park, or community venue on Mercer Island? We help you identify which business to contact and provide the details they'll ask for.
Seattle-Tacoma International Airport
If your loss happened at SEA Airport, the lost and found office on the Baggage Claim Level is your first stop. We can direct you to the right contact method.
Lost pet?
A lost dog or cat needs faster action and different channels than other items. The Seattle Animal Shelter, local animal rescues, and community pet networks should all hear about it immediately. File a priority lost pet report
⚠️ Spotted incorrect or outdated information? Let us know so we can review it.
Here are the offices that take your report.
The sooner you report it, the sooner your search can start working for you. Your report goes live across all the right channels, and you're no longer responsible for checking each one every day.
Report my lost item →Losing something on Mercer Island means reaching out to separate places, one by one: the island's police department, individual businesses, Island Transit, local Facebook groups, and neighborhood apps. Each one has its own hours and process. Meanwhile, hours slip by, and the trail grows cold.
ReportLost turns that chaos into one simple action. You file one report with us, and we immediately notify the Mercer Island Police Department, check the right local channels, and keep your report actively searching for a match across community networks for 12 months. Once you've reported it, you can stop worrying and let us do the legwork.
Common places where things get lost on Mercer Island
Include your specific location when you report, and we'll make sure the right department knows where to look.
Downtown Mercer Island
The commercial heart of the island, with shops, restaurants, and gathering spots where wallets, keys, and phones frequently go missing.
Island Transit stations and buses
Items are regularly left on buses or forgotten at shelters. Reporting to the transit lost and found immediately improves chances of recovery.
Parks and trails
Mercer Island's green spaces and waterfront areas are popular for recreation. Jackets, sunglasses, and personal items are often left behind.
Residential neighborhoods
The Lakes neighborhood and other residential areas see lost items near driveways, yards, and community streets.
The waterfront and beach areas
Items lost near the shoreline or during water activities may wash away or be turned in to nearby businesses.
Community networks watching for your item
Mercer Island residents actively share lost and found posts on these platforms. Your report gets the word out.
Facebook community dedicated to reuniting residents with missing items
Active neighborhood group where residents post lost and found items
Broader regional subreddit where Pacific Northwest lost and found posts sometimes surface
Neighborhood alert app used by many Mercer Island residents to flag missing items
Questions about losing something on Mercer Island
How long does the Mercer Island Police Department keep lost and found items?
Items turned in to the Police Department are typically held for a set retention period. Contact the Police Records Division at (206) 275-7610 or check with them directly about specific timelines for your item.
Where do I pick up my lost item once it's found?
If your item is found and held by the Police Department, you'll need to visit or contact them at 9611 Southeast 36th Street, Mercer Island, WA 98040. If it's at a business or transit facility, they'll provide pickup instructions.
What if I lost something on Island Transit?
Contact Island Transit's Lost and Found office at (360) 678-7771 (Monday through Friday, 8am to 4pm). They hold items for a limited time, so calling quickly improves your chances.
How do I report a lost item if I'm not on the island right now?
You can file a report with ReportLost from anywhere, and we'll notify the relevant Mercer Island departments and community channels on your behalf. You don't need to be on the island to start your search.
Can I search lost items that others have posted online?
Yes, check the Mercer Island Lost & Found and Mercer Island Neighbors Facebook groups, as well as Nextdoor and Craigslist. However, with ReportLost, you don't have to spend time searching these yourself, your report stays active and we cross-check new posts automatically.
Is ReportLost.org official or affiliated with the Mercer Island Police Department?
ReportLost is an independent service, not part of the Police Department or City of Mercer Island. We're a third-party platform that helps you notify the right departments and community channels all at once, and keeps your report actively searching for matches. Filing with us doesn't replace reporting to the police, but it streamlines the process and ensures nothing falls through the cracks.
Lost & found in nearby cities
Your report is your best tool
The moment you file with ReportLost, your item is being looked for across the Mercer Island Police Department, local businesses, transit services, and community networks. You've done your part, and now your report works for you around the clock.
Start my report →ReportLost.org is an independent service and is not affiliated with the Mercer Island Police Department, City of Mercer Island, Island Transit, or any other listed organization. We help you notify these entities and keep your report active in community channels, but we do not replace official police reports or agency lost and found systems. Always report valuable or legally significant losses to the appropriate authorities directly.