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General Section

The East Lake Sammamish Master Plan Trail is an alternative non-motorized transportation corridor and multi-use recreational trail along 11 miles of former Burlington Northern Santa Fe (BNSF) railroad corridor on the east side of Lake Sammamish, from Redmond to Issaquah. King County purchased the corridor in 1998 and opened an interim gravel trail in 2006. King County Parks (Parks) has spent more than 10 years on master planning, design work and environmental coordination with the cities of Redmond, Sammamish, and Issaquah.

The ELST is an integral part of King County’s regional trail system. The improved trail will provide greater safety and accessibility for people of all ages and abilities. The ELST is currently the 11-mile “missing link” in the 44-mile long regional trail corridor that will connect the Burke-Gilman Trail, the Sammamish River Trail, the Marymoor Connector Trail and the Issaquah-Preston Trail, linking Seattle to the Eastside and the Cascade foothills. The trail will provide greater access to recreation, employment and retail in the cities of Redmond, Sammamish, and Issaquah and provides a multi-use path for bicyclists, pedestrians, joggers, and skaters.

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View of Lake Sammamish from the North Segment of the East Lake Sammamish Trail

Yes. King County purchased the railroad corridor in 1998 and acquired all of the property rights held by BNSF. At that time, the ELST corridor was “railbanked” under the federal “Rails to Trails” Act. “Railbanked” corridors are preserved for possible future reactivation of rail service and trail use is authorized on an interim basis. A recent Federal Court decision confirmed that King County acquired all of BNSF’s property interests and has exclusive right to possess and control the corridor.

King County is designing and constructing the East Lake Sammamish Trail corridor in phases as funding becomes available. The segments, and location of each are as follows:

  • Redmond Segment – NE 70th St. to 187th Ave. NE (1.2 miles). Parks opened the first segment of the Master Plan Trail in Redmond in November 2011.

  • Issaquah Segment – SE 43rd Way to Gilman Blvd. (2.2 miles). The Issaquah segment opened in June 2013.

  • North Sammamish Segment – 187th Ave. NE to NE Inglewood Hill Road (2.6 miles). Redevelopment of the North Sammamish segment began in April 2014 and opened in July 2015.

  • South Sammamish Segment A – SE 43rd Way to SE 33rd St.- approx 1.2 miles. This segment is currently closed for construction and is anticipated to re-open in January 2018.

  • South Sammamish Segment B – SE 33rd St to Inglewood Hill Rd. - approx 3.6 miles. This segment is currently in design.

  • Inglewood Hill Parking Lot – Currently under 60% design review.

  • 33rd St. Parking Lot – Design for 33rd St parking lot will begin in 2019.

Trail Design and Development

Trail safety is a top priority for King County. The new trail has been designed to meet all applicable engineering and safety standards. The trail design clearly identifies intersections with consistent signage, striping, and bollards. Safety design features include:

  • Providing open sightlines for trail users, motorists, and pedestrians crossing the trail;
  • Providing a visual and textural difference from the asphalt trail by constructing concrete intersections;
  • Warning trail users of approaching intersections with textured concrete warning bands 75 feet ahead of each crossing;

View of an improved intersection from the North Segment of the East Lake Sammamish Trail

Safety is King County’s highest priority. Intersections are designed to comply with federal and state design and engineering standards that ensure adequate visibility at intersections. Sight distance triangles allow trail users and vehicles crossing the trail to clearly see one another. Sight distance triangles for the East Lake Sammamish Trail are calculated from the perspective of the intersecting vehicle. Vehicle sight distances are based on national standards outlined by AASHTO in Policy on Geometric Design of Highways and Streets, 2011 (Green Book). A detailed explanation of how King County determines site distance triangles and why other standards are not used is available for review or download on the project website:, under South Sammamish A or South Sammamish B / Project Guides / Sight Distance Triangles.


Example of improved sight distance triangle at an intersection along the East Lake Sammamish Trail

Yes. The trail is designed to regional and national trail safety standards, as defined by the American Association of State Highway and Transportation Officials (AASHTO) and Policy on Geometric Design of Highways and Streets, 2011 (Green Book The existing stop signs were installed as intersection controls for the existing gravel trail. Now that the trail is being redeveloped into a paved shared use path, the type of use and volume of use are expected to change and the intersection design must be updated to ensure consistency with all applicable safety standards.

Additional information regarding the appropriate placement of stop signs can be found on the project website:, under South Sammamish A or South Sammamish B/project guides/Stop Sign Usage.

The trail design and alignments are developed by balancing the following considerations:

  • Complying with local, state and federal environmental regulations to avoid and minimize impacts to environmentally sensitive areas
  • Meeting regional trail standards and national safety guidelines, including maintaining clear sight distances
  • Staying within the King County corridor
  • Building a safe trail by adhering to the standards and guidelines in the American Association of State Highway and Transportation Officials (AASHTO) and Policy on Geometric Design of Highways and Streets, 2011 (Green Book)
  • In addition to accessibility and safety, King County Parks considers recreation and aesthetic values as part of the siting, design, and development of its regional trails
  • Minimizing costs where possible without impacting trail standards
  • Minimizing impacts to adjacent homeowners
  • Preserving significant trees

Examples of existing conditions along South Sammamish Segment B

The ELST is a being designed and constructed as a 12-foot paved trail with two-foot gravel shoulders and a one-foot clear zone on each side. This width is necessary to meet the projected volume and variety of trail users. A recent analysis has estimated the volume of bicyclists, pedestrians and other users on the ELST will increase from 514 per peak weekend hour by 2020 and over a thousand by 2035. The ELST has been designed not just to meet the immediate need and but to accommodate expected future growth. The width of the ELST is consistent with national design and safety standards based upon the estimated volume.

Landscaping and Vegetation

Removal of some vegetation is necessary to allow construction of the ELST. This means clearing beyond the edge of the existing trail to build the new wider trail, retaining walls, environmental features, and drainage improvements. After construction, King County will install new landscaping and restore areas disturbed during construction. All vegetation removal is being done within King County's trail corridor.

The project includes new plantings to restore the project area and achieve the following objectives:

  • Open sightlines at all intersections to improve safety. Areas within the sight distance triangle will be restored with plants that grow less than three feet high at full maturity
  • The most immediate function of trail landscaping is to restore exposed areas with landscape mulch and plantings or seeding to prevent erosion
  • Native plants, shrubs, and groundcover offer many benefits; they are well adapted to thrive in local conditions of drought or excess moisture; they require less maintenance, growing to natural sizes and forms; and they blend well into the natural surroundings along the trail corridor
  • Contribute to a sense of visual continuity along the trail corridor and help make the trail feel like a park

Examples of landscaping along the East Lake Sammamish Trail


King County will remove only those trees within the limits of construction and trees that are impacted by construction. Unhealthy trees that pose a safety risk (as determined by an arborist) will be removed as well. King County is committed to preserving significant trees along the trail whenever possible. Trees provide natural habitat for birds and wildlife, and shade and screening for trail users and neighbors.

As defined in the Sammamish Municipal Code, significant trees are coniferous trees with a diameter of 8 inches or greater and deciduous trees with a diameter of 12 inches or greater at breast height (DBH), or approximately 4 ½ feet above ground.

King County has and will continue to mitigate the removal of trees and vegetation by landscaping the trail corridor using the criteria outlined above.

The North Sammamish Segment included King County planting 1,150 trees, over 11,000 shrubs and plants, and restored one acre of wildlife habitat.

In the remaining trail segments, King County is proposing to apply the same approach.

Streams and Wetlands

Wetlands, streams, and ditches are identified and delineated by the project scientists (wetland biologists) using city, state, and federal environmental regulations and guidance. Over the last 14 years, the environmental conditions along the East Lake Sammamish Corridor have been thoroughly investigated. The findings are documented in the segment-specific Critical Areas Study. The federal, state, and city permitting agencies which regulate wetlands, streams, and ditches review, verify, and make the final determination of these features during the permit review process.

The East Lake Sammamish Trail is bordered by more than 70 wetland areas. These areas are sensitive and play a critical role in the Lake Sammamish habitat. Protecting these wetlands is an important part of maintaining a healthy ecosystem and is part of King County’s ongoing commitment to the environment.

King County’s trail improvements are consistent with the Shoreline Management Act. One goal of the act is to prioritize public use and enjoyment of the shorelines. This project is consistent with that goal. King County has extensively investigated the critical areas along the trail corridor and the associated regulatory requirements, as documented in the Critical Areas Study – the segment specific study can be found on the East Lake Sammamish Trail website.

King County has been coordinating with and continues to coordinate with the Lake Sammamish Kokanee Work Group. In South Sammamish Segment B, eight fish passable culverts will be constructed to provide fish passage to streams for spawning habitat. These improvements will be occurring on streams identified by the work group as the highest priority for Kokanee.

The North Sammamish segment included constructing five fish passable culverts and enhancing approximately one acre of habitat improvements.


Examples of fish culverts along the East Lake Sammamish Trail

The Environmental Impact Statement (EIS) Section 3.4.6 discloses potential impacts to wildlife. Provisions for allowing wildlife passage at intervals along the trail include: the use of split rail fencing adjacent to environmentally sensitive areas such as wetlands and streams, intersecting driveways, and gaps between the fences. The EIS is available for review or download on the project website.

Permitting, Review Process, and Communications

  • Per the City of Sammamish’s code, the City of Sammamish will receive public comment from December 28, 2016 to January 27 2017. All public comments must be submitted to the City of Sammamish.

  • King County has made the 60% design plans available for review by posting them to the project website at

  • Upon completion of the public comment period, the City of Sammamish will forward all comments received to King County for review and consideration. The County will provide responses to all comments in the following months. A representative of the project team will be available at Sammamish City Hall on specific days and time to answer questions or provide clarification to homeowners and other project stakeholders regarding the design plans. You may schedule a meeting thru the project website, contacting the project hotline or thru the project email at The County appreciates you taking the time to provide comments through the important permitting process.

King County has established a robust public outreach program to engage the community in the design and construction process of the East Lake Sammamish trail. The public outreach program includes:

  • A 24/7 hotline – 1-888-668-4886
  • Project email –
  • Project website –
  • You may follow our blog:
  • You may click on the Facebook logo to Learn about King County Parks
  • For the latest King County news: you may go to Twitter logo @KC News
  • Email alerts
  • On site meetings with trail neighbors
  • Open houses
  • Notification letters
  • Information flyers
  • and more

In order to assist adjacent property owners in evaluating this proposal, King County has surveyed and staked the proposed trail centerline and the limits of King County’s property in the ELST corridor.

During trail construction, the project team will post weekly construction updates that include upcoming construction activities to the project website and public outreach staff will be on-site to provide clarification, notifications, and listen to comments and concerns from homeowners and trail users.

King County encourages homeowners, trail users and other stakeholders to take advantage of the several opportunities available to communicate with the project team during trail design and construction.

Trail Construction

Yes. King County closes segments for construction due to the extensive scope of work within the narrow trail corridor and limited trail access. Closing the trail is necessary to protect the public and to ensure maximum safety for all. King County is mindful of the impact of construction on neighboring property owners and is working to ensure the Contractor completes the project on time.


Construction crews working on a closed portion of the East Lake Sammamish Trail

Constructing the trail is challenging and difficult due to the narrow corridor, limited trail access, and steep topography. Additionally, there are seasonal constraints on construction near streams, construction of retaining walls, mitigation and landscape planting, and redevelopment of the intersections. The East Lake Sammamish Trail segments are particularly challenging due to the close proximity to adjacent private property, and multiple intersecting driveways and property access points along the trail.

Project Funding

Funding for the South Sammamish A segment is provided by the 2014-2019 voter-approved Parks, Trails and Open Space Replacement Levy (Proposition 1; August Primary Election 2013) and grant funding provided by the Washington State Recreation and Conservation Office.