I'm surprised that this movie got such high user ratings and reviews. It is as though only Hoppy fans vote here and mindlessly give everything a 7 vote.
I thought this was one of the worst Hoppy movies. I enjoy most of them. The story was uninteresting. The supporting cast was mediocre. Victor Jory should have remained as a bad guy; here he looked ridiculous with his silly accent. The singing was corny. Andy Clyde's antics was inane and juvenile. There was some decent camera-work and action.
The final action scenes in the film demonstrate without doubt how poor this movie is. Hoppy gets word that the bad guys are on their way to blow up the dam with dynamite. So Hoppy returns to his camp, and with his sidekick Johnny they ride a log through the sky (the timberline of the title) to reach the dam and the bad guys, who shoot a fusillade of bullets at them, merely slightly wounding Johnny. So after miraculously arriving at the dam in the nick of time and unhurt, Hoppy (who happened to spot the bad guy planting dynamite with a lit fuse at the base of the dam near the water) dives off the dam into the water and swims to the lit dynamite. I couldn't believe he could dive that distance into the water with his hat on and swim to the planted dynamite, with his hat still on! Still immune to the fusillade of bullets, he conveniently throws the dynamite quite a distance to the bad guys blowing them up. The final scene in the movie was particularly embarrassing. As Hoppy and his pals are saying goodbye to all assembled, sidekick California says he forgot his hat, and everyone laughs as though it was the funniest thing they ever heard.