While driving back toward Teslin on Tuesday, with thick fire smoke filling the air, I saw a couple walking on the shoulder of the road a few kilometers before the Lower Rancheria River. Going by the rest area there, I saw a small plane parked out of the way at the rest area. A few miles later, I realized the couple and plane could have been connected, so I pulled a u-turn, caught up to the couple and was told that they had to make an emergency landing on the highway due to the lack of visibility. They were walking to the top of the hill to see if it was clearer on the other side. I told them it didn't look any better. After offering them a ride, etc.., they refused. If need be, they told me that they had enough supplies in case they had to overnight.