Peak 3700 is a bit of an adventure, but certainly do-able summit near Detroit, Oregon. You'll follow a long-abandoned logging road and head cross-country for the final ascent into the Activation Zone. There are no views and the final ascent is very rough, but you get to enjoy the quiet of a second-growth forest.
About three miles south of Detroit, Oregon on Highway 22, take Blowout Road. There's a card-lock gas station and an espresso stand across the street. Cross a bridge and at about 1 mile you'll turn left onto a gravel road - NF-1003. The roads are all in good shape and can be driven in a passenger vehicle. After about 4.2 miles, you'll turn right onto NF-409. After about 1.1 miles, you'll see NF-412 - park here as the road becomes unpassable shortly after the intersection.
You'll walk up NF-412 about 0.1 miles, where you'll find a gate on the left for NF-413. The road seems to disappear on occasion, but does continue for about 0.7 miles where it stops climbing about 0.15 miles from the summit. From here you'll pick you way up the slope cross-country until you reach the Activation Zone in a dense cluttered forest.
After activating, we found another very faint abandoned road near the AZ and followed it back down to NF-413. The roads have been left for many years and can be a bit challenging to follow - a GPS will help you find the summit, make sure you are in the AZ, and give you clues for tracing your way back to the car.
You might consider doing another nearby summit while you are here - Blowout Benchmark - as it is just up NF-409 past the parking spot for Peak 3700.