Grand Ridge is both an oldie and a new trail: while new residential development wiped out some of the trails we rode in the past, a new trail system has been under development by King County Parks and the WTA. (Check out wta.org for work parties.) You access it the same way as ever: by climbing up from I-90. The trail can also be accessed from the top of the Issaquah Highlands development.
The main trail winds north across Grand Ridge towards Duthie Hill Park.
This is a great XC work out, with great climbing practice. Plus, it can be linked with trails on the south side of I-90 to create longer loops. This trail connects with Duthie Hill Bike Park and 1 short mile of road riding to continue up to Soaring Eagle for a suburban epic.
The climb from I-90 up to the plateau is a grunt, but not too long. When coming from Duthie Hill, the long climb up to Grand Ridge Drive is even more of a grunt, and is pretty darn hard to clean on a single speed. With gears, it's still a fairly physical ride.
This trail is also a great night ride.
THIS TRAIL IS NOT AN OFF LEASH AREA.
Grand Ridge can have quite a few puddles during and immediately after a rain as there are quite a few springs and a lot of the soil doesn't drain very well. Lots of leaves in the fall can make for a really wet ride. If you want modestly dry conditions you should wait 5 or so days after a big rain.
Not crowded but does get a few hikers, families with small kids and dog walkers. Please be cautious of hikers on this trail, and consider wearing a bell so they can hear you coming. Horses are rare but new bridge means there will be more.
One can debate about food, but the best beer in the vicinity as at the Issaquah Brewhouse, which has some 20 taps and many Rogue beers on tap. The Brewhouse is on Sunset Way, just west of Front Steet, Issaquah's main drag. The easiest way to find it coming back from Exit 20 is to take Exit 18, take the Sunset Way split, and go straight until just past the light at Front St.
As a resident of Issaquah, my favorite place to stop after a mountain bike ride is Extreme Pizza on Front street. Super friendly service, fresh ingredients (for example- they make their own hummus for their hummus pizza!), beer on tap and even gelato!