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Regional Scheduling Office
Tel: 206-477-6150
E-mail:Regional Scheduling

Marymoor Reservations
Marymoor Park Office
Tel: 206-205-3661
E-mail:Marymoor Scheduling

Aquatic Center Banquet Hall
King County Aquatic Center
Tel 206-477-4444
E-mail: Aquatic Scheduling

For any other inquiries please contact Parks Info

Parks and Recreation Div.
201 S. Jackson St., # 700
Seattle, WA 98104
TTY: 711

Black Diamond Open Space 

Proposed Trail Development
King County Parks is considering a proposed project to develop trails and mountain bike-oriented facilities in the general area of the power lines.

Final Conceptual Plan

Advisory Committee Recommendations (June 2014)

Informational Meeting - 03/26/2014

Advisory Committee Meeting - 05/01/2014

Advisory Committee Meeting - 05/22/2014

Black Diamond Open Space (BDOS), which is located in rural King County outside of the city of Black Diamond, is comprised of multiple sites totaling 1,100 acres owned by King County Parks and 80 acres in conservation easement. 

Black Diamond Open Space is managed as three geographic units:

North Unit
This area is the largest and most publicly used portion of BDOS. It is located north of the city of Black Diamond on both sides of SR 169 and includes Ravensdale Lake and  Creek. The lake, creek corridor, and a few large wetlands have a forested buffer; most of the site is young forest or shrubs. Trails appropriate for non-motorized use crisscross the property, with the main point of entry off of SR 169 (where King County is currently constructing parking lots). King County Parks' Green-to-Cedar River Regional Trail is planned for future development through this unit, west of SR 169.

Southwest Unit
This land is mostly steep forested slopes in the vicinity of Crisp Creek, off of 218th Ave SE, southwest of the city of Black Diamond.

Southeast Unit
This area is located near Icy Creek and the Green River in the vicinity of SR 169, southeast of the city of Black Diamond. The property supports stands of young and mature forest, located adjacent to hundreds of acres of public lands managed by Washington State Parks and Washington State Department of Fish and Wildlife. A small amount of additional acreage directly southeast of the city of Black Diamond is also a part of this unit.

The 1996 Black Diamond Urban Growth Area Agreement identified open space lands around the city for permanent preservation on the principle that for every one acre of urban land added to the urban growth area, four acres would be permanently preserved as open space ("4 to 1 agreement"). Two phases of annexations in 2005 and in 2009 dedicated most of the Black Diamond Open Space site currently in King County ownership; an additional phase or two of land dedications are anticipated between 2014 and 2021. Property purchases have also added acreage to the site over the years.

About the 2005 Black Diamond Open Space Protection Agreement
(between King County, Black Diamond, Plum Creek and Cascade Land Conservancy) 

Useful links 

Henry's Ridge, Black Diamond & Ravensdale Retreat

Henry's Ridge

Black Diamond

Proposed Trail Development Contacts
Butch Lovelace, King County Parks

Glenn Glover, Executive Director
Evergreen Mountain Bike Alliance
418 NE 72nd Street
Seattle, WA  98115
Tel: 206.524.2900

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