You can have good ankle dorsiflexion and still have good calf stiffness. I would start with ankle dorsiflexion static stretches to get your heels on the ground more when hiking up hills. Having your lower legs on fire on the uphills is not ideal. When muscles relax, blood can flow into them and help with that burning feeling. But not being able to go through a normal range of motion in your ankle, you are keeping these lower leg muscles too tight for too long
Can you get into a deep squat? Butt down close to the floor, heels flat on the floor. Stay there as long as you can. This will help your hips and ankles. You must have good ROM in all your leg joints, or you will put undue stress on other joints.
Jumping rope, two feet at a time, off your toes will help build muscular endurance in the lower legs. Locked knee, toe bounce is another way.
I suggest a two-pronged approach. Increase dorsiflexion ROM and some calf ME work.
Scott