Clint paints the Western town red, like Gehenna
This was Clint's third directorial effort (although he also did some uncredited work on "Dirty Harry"). It parallels his "Pale Rider" from a dozen years later with the difference that Preacher from "Pale Rider" is essentially righteous and therefore protects worthy people whereas Stranger in this flick is vengeful, focusing on dishing out retribution to those who are bad. The fact that there are few 'good' people in Lago makes you root for the Stranger, to a degree, but it also prevents the viewer from having compassion for the townsfolk.
There's also an emptiness and tediousness to the proceedings that works against the movie and explains why I slightly prefer "Pale Rider," which was basically an 80's reimagining of "Shane" with the addition of a vague supernatural angle. Still, "High Plains Drifter" is an iconic Eastwood Western and holds up in its unique, nigh satirical way.
It was shot at Mono Lake, California, which is northeast of Yosemite National Park (with the west side of the lake being in the park), as well as Winnemucca Lake, Nevada, which is about 170 miles due north of Mono Lake.
The beautiful Marianna Hill plays the blonde, Callie. She was 30 years-old during shooting. You might remember her from the Star Trek episode "Dagger of the Mind" from seven years prior. She was one of the most winsome women to appear on Star Trek and had gigs in numerous television shows throughout the 60s and 70s, as well as quite a few films like Elvis' "Paradise, Hawaiian Style," this one, and even starred in the atmospheric horror flick "Messiah of Evil" (aka "Dead People"), which came out the year after this. It was the pinnacle of her career and she faded out of acting after 1977.