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greenBlue Mainline

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0.7 mile 1.2 kilometer point to point
97% Runnable


Ascent: 73' 22 m
Descent: -59' -18 m
High: 598' 182 m
Low: 567' 173 m


Avg Grade: 3% (2°)
Max Grade: 9% (5°)


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Trail shared by Brendan Ross

The main entry into Lake Sawyer's trail network, leading visitors to a wide variety of singletrack options.

Brendan Ross

Features -none-

Runner Notes

Despite being directly across Highway 169 from the more popular Black Diamond Open Space trails, Lake Sawyer Trails have a distinct personality all their own. They tend to be more rugged, with plantlife reflecting their proximity to the lake, rivers, and sloughs that run through the area. With all that water comes a noticeable increase in humidity, and the 10-20% boost can be especially noticeable on hot days. The trails here also receive less maintenance than those on the east side of the highway, so be on the lookout for blackberry vines and stinging nettles or other areas of overgrowth.


Starting at the Lake Sawyer Trails parking lot, Mainline is most runners' entry point into the system west of Highway 169. A short gravel segment parallels the southern end of the parking lot, and quickly turns into a dirt doubletrack as it enters the trees. Don't be put off by the somewhat rocky conditions as the trail begins, as it isn't characteristic of most of Lake Sawyer's network.

The turnoffs to area trails begin almost immediately, and this is a good place to intentionally get lost on a run for a while. Most are signed, but signs here are often a little harder to see than in Black Diamond Open Space to the east. Most signage are vertical and posted about eight to ten feet up on a tree set back a bit from the entrance, so look up.

After passing Old Railroad Grade, Mainline narrows to a singletrack and the rocks ease up just a little (but not much). Hang right at the fork where Mainline crosses Lake Sawyer RR Company, named after an old area railroad cutting directly through the trails, and descend a short here. You'll start feeling the humidity off the area's water features at the bottom as Mainline continues to pass turnoff after turnoff. Generally, going right will put you deeper into the system, and left heads back towards the highway. It's mostly flat from here until the end.

Most of the trail is well-covered and shady, though you'll pass through a small clearing at the southern end of Lake Sawyer RR Company. Continue ahead as the trail slowly curves to the east and passes through an open air segment just before ending at Old Railroad Grade opposite Mistress. As mentioned earlier, the sign on this end is set back from the intersection a bit. Continuing straight can make a nice short loop back to the parking lot, or turn south to continue exploring.


Land Manager: King County Parks

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Trail Ratings

  3.0 from 1 vote


in Lake Sawyer


  3.0 from 1 vote
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