UPDATE: Many trails on the Oregon side of the Columbia River Gorge are closed because of damage from the 2017 Eagle Creek fire. As of June 2018, the Larch Mountain Road to the summit is still closed. Check the list of CLOSED recreation areas before you plan for a ride.
When I am in Portland and want to get out of town for a fun, challenging uphill, this route is at the top of my list. From nearly any point on the east side of Portland it is a 25 minute drive to the start and on most weekdays the traffic on Larch Mountain is light. Weekends are less tempting as many sightseers will drive up to the Larch Mountain parking area for the short hike to Sherrard Point, where they can view the local Cascade mountains.
You gain about 3400' on this ride, but the grade is never too challenging and it is only 14 miles so you never quite reach the "Are we there yet?" point. When you only have a few hours to spare for a ride but want to get in a solid climbing workout, you can hardly ask for better.
GUIDEBOOKS & MAPS
June - November. The Larch Mountain Parking Lot is at over 3900' and the upper portion of the road is closed during winter. The road is typically opened sometime in June and you can check the Forest Service page for current conditions. Even in summer it can be chilly and wet up here, so check the forecast beforehand to ensure you wear the right gear.
There are multiple places where you can start this ride, everything from Lewis & Clark State Park to Vista House, but I prefer driving to the Portland Women's Forum State Park (map) and starting there. It has plenty of parking and while you are getting ready you can enjoy an early morning view of Vista House with the Columbia Gorge in the background.
Take a left out of the Portland Women's Forum parking lot and in less than half a mile you turn right onto Larch Mountain Rd. The first couple miles are rolling hills with homes and fields all around. Eventually, you head into the forest and begin a fairly steady 9 mile climb.
The grade mostly sticks in the 4-7% range with a few minor downhills to give you a brief respite from the climbing. You top out at the Larch Mountain Parking Lot where there are multiple trails for hiking.
At the very end of the parking lot is a double privy off to the left. Off to the right is a 0.3 mile paved trail to Sherrard Point, which has views of all the local Cascade volcanoes. Early in the mornings, you can ride your bike along this paved trail until reaching the stairs, where there is a quick climb up to the viewpoint.
The return trip is nearly 14 miles of downhill on reliably good pavement. The forest can make the rough spots a bit hard to see so stay vigilant on your long descent. It's a pretty fun downhill so enjoy yourself.
Back at the Women's Forum put your gear away and if you are a bit peckish, the Corbett Country Market is on the way back to the interstate and has many options for snacks.