Single Engine Cessna Pilot reported inadvertently taking off from a road paralleling the runway at an isolated airport. The aircraft's wingtip clipped an overhanging tree and removed the cover of the navigation light.

Narrative

ZZZ is a back country strip. The strip sits at an elevation of 5912 ft. and is 2765 ft. long x 75 ft. wide. Runway numbers are XX and XY with landing recommended on XY and takeoff on XX; weather permitting. It is gravel with a gravel road on each side of the strip. I landed at XA00 without incident. This was my first time into this particular strip; but I have experience in the backcountry and have landed on similar strips prior to this. Upon landing; friends who had flown into the strip before encouraged me to taxi to the end of the runway as my husband is in a wheelchair and they thought it would be easier for us to get around. I was actually parked at the very end of the runway. We walked into town for lunch and returned to the strip for takeoff about 90 minutes later. There was a breeze of 5-7 kts. (a tailwind); but all pilots present felt the recommended takeoff on XX would be the best option. Since it is a relatively short runway and high elevation I wanted to use as much of the runway as possible for takeoff. When I began my takeoff roll; I mistakenly thought I was in a tie down area (instead of the actual end of the runway) and I started working my way to the left on what I thought was the runway but was actually a road right next to the runway. I continued to gain speed and was going about 20 kts. when I saw a small hole in the road and my left main hit the hole and it was at that point that I realized I was on the road. I adjusted my takeoff roll slightly to the right and was back on the runway. The takeoff proceeded without incident and we flew back to our home airport. The fuel truck from the local FBO came out to fuel the plane and noticed that a piece of fiberglass had come off the left wingtip and the red cover from the nav light was missing. I did not know how that had happened. I thought I had just hit a small hole. Some friends that had flown up with us in another plane stopped by and told us that on takeoff I had actually clipped a small evergreen tree on the road that I had mistaken for the strip at the beginning of my takeoff. They returned the red nav light cover to me along with a few pieces of fiberglass. I must have clipped that little tree when I thought I was hitting the hole with my left main. No one was hurt. Nothing was damaged but a piece of the fiberglass covering on the left wingtip. The nav light was still working. The cause of this incident was my unfamiliarity of this particular strip plus the fact that the road is right next to the runway. I will not have this problem again because I am now familiar with the strip. To prevent this from happening to others - maybe some kind of flags or markers at the end of strip would be beneficial. Also; if I had parked where everyone else parked; I probably would not have had that problem.