Cycling Out Of Sumner (COOS) #10: Lake Washington Half Loop


  • Advance registration required for all participants. If you decide not to ride, please click Cancel My Registration below to open space for others. (How to cancel
  • Attendance at the pre-ride safety briefing is required to participate in the ride.
  • If you have tested positive for COVID or have been exposed to someone with COVID, follow the quarantine and isolation guidelines. In general, if you have COVID or are displaying COVID symptoms, or if you are sick with the flu or a cold, you should not participate in group rides.
  • Carry a face covering in case a business or public transit requires their use.
  • Please, no spitting or “snot-rockets” while participating.
  • A CPSC certified helmet is required to be worn to participate.

If you are new, please read our newcomer information.

Date and Time: 
Saturday, June 10, 2023 - 8:00am
Start Location: 
Fred Meyer (southeast corner of parking lot)
1201 Valley Ave
Sumner, WA 98390
Contact Information: 
Co-Series Director
Emily Anne Mozzone
(425) 495-6446
88 miles
Elevation Gain: 
2,012 feet
Weather Cancellation: 
E-bike friendly
New Riders
Fitness / Health

Cycling Out Of Sumner (COOS), a spring training series, continues with three paces offered (Steady 12 - 14 mph, Moderate 14 -16 mph, Brisk 16 - 18 mph). COOS is running for thirteen Saturdays, from April 1st through July 8th. COOS is a training series to build endurance and strength. The rides will incrementally increase in distance, leading up to a century (100 miles). All paces will use a common route each week. 

Let's meet at the east corner of the Fred Meyer parking lot.  Please be ready to ride at the start time. We will start with a required safety briefing and roll out when that's done.  If you miss the briefing you will not be able to ride with the group.  It's a good idea to arrive early!  While there is plenty of foot traffic at our start location, property crime can happen in a moment: do not leave bikes or other valuables unattended.

We will climb and descend hills at our own pace, and our goal will be to regroup after hills and before turns. We'll also limit our speed on any multi-use paths to the legal maximum (usually 15 MPH). All riders should carry nutrition and water, and have the know-how and equipment to fix a flat tire, as well as to make minor repairs. Everyone should carry a phone to call for assistance if needed, as well as cash, and/or a credit card.  Ride Leaders will not be providing cue sheets.  Riders may choose to view the route online, download to their own devices, and print a cue sheet if desired.

New riders, we are very happy to have you with us! Please read the information found at the "New Rider" link and keep in mind that a helmet is required for all Cascade rides.

Please register for the ride using the red "Register Now" button at the top of this page.  On-line registration and waiver sign is required for all participants. 

For ride #10, we will head north via the Interurban Trail then through Renton to complete a Lake Washington half loop around Mercer Island. Then after stopping on Mercer Island for some food and a break, we'll head south on the Seattle side and back to Sumner. Bathrooms are available at: mile 0.0 at Fred Meyer, mile 8.2 at Auburn's Wal-Mart, mile 25.1 at Renton's Gene Coulon Park, mile 45.5 at various Mercer Island businesses, mile 52.3 at Seattle's Seward Park, and mile 70.3 at Kent's Hogan Park. Our longer break will be on Mercer Island, where you are welcome to buy yourself a quick lunch at various businesses such as McDonald's, QFC, and Met Market. We'll also stop for a little bit at the East Portal Viewpoint (mile 48.5) to check out the gorgeous view! 

Note: Weather cancelations will be in the ride post title at least 2 hours prior to start time and registered riders will be sent a cancelation message to their email address attached to their Cascade account. If the ride is canceled at least 2 hours before the start time, ride leaders will not be at the start location. 

We hope you can join us!


Looks like it will not be raining much. We probably will not cancel, but check for a cancelation 2 hours before the ride time. If the ride is canceled at least 2 hours before the ride time, it will be noted in the ride post title and all registered riders will be sent an email. If ride is canceled at least 2 hours in advance of start time, ride leaders will not be at the start. If weather is miserable while riding, ride leaders may decide to cut it short (by altering the route). Fenders if roads are wet. SMART talk should discuss some extra caution for riding when it is wet and possibly slippery in places. 

Fred Meyer (southeast corner of parking lot)
1201 Valley Ave
Sumner, WA 98390

Registrations so far...
Steady: [12-14mph]

9 rider(s)

Moderate: [14-16mph]

29 rider(s)

Brisk: [16-18mph]

17 rider(s)