Leif Erikson roughly follows the contour along the length of the park, making for a nice, long dirt-road ride. On nice weekends, it’s a bit crowded with pedestrians near the Thurman trailhead but gets open a mile or two out. It’s somewhat muddy during wet periods.
This ride has a loop up Saltzman Road
and down Firelane 5
(the only very short bit of singletrack) thrown in. I think it's more fun to ride up Firelane 5
, then turn back down where it crosses the Wildwood trail than going up Saltzman Road
or riding Firelane 5
above Wildwood. Either way, this loop is easy to adapt for your preferences.
Overall, this is not a prime NW mountain bike experience, but can still be a nice gravel/road ride to escape from cars into a forest. It's also a popular workout for training cyclocross and gravel riders.
The fire lanes this ride intersects can be fun diversions - they are steep, short roads generally going uphill from Leif Erikson Drive
The park was nearly all logged, so it’s second-growth successional forest with a few large (by NW standards) old trees.
Although Forest Park is one of the largest urban parks in the country, opponents of cycling (mostly park neighbors) shut bikes out in the 1980's and 90's, and have prevented bikes from getting trail access. So this route is not mountain biking but has dirt/gravel road riding. The only short trail segments are on Firelane 5
(about 1/3 of a mile) and northerly parts of Newton Road
, which are trail-like for less than a mile. Northwest Trail Alliance and others have worked for many years to get singletrack open to biking.