Are there still any public school systems in the U.S. that do not teach evolution?

[wimp]

.

[Senate Minority Leader Lord Voldemort]

I'm sure there are a ton of small schools in rural areas where it is in the official curriculum but the teacher just skips over it.

[emailking]

Or they just teach it as a competing theory with intelligent design, thus downplaying it.

[Blue3]

What those two said ^

[Progressive Pessimist]

With the way things are going today, expect more states to start being more blatant about it. History is going to repeat itself with the Scopes trial, nearly 100 years later.

[dead0man]

some recent science on the matter

Abstract
Background
Over a decade ago, the first nationally representative probability survey concerning the teaching of evolution revealed disquieting facts about evolution education in the United States. This 2007 survey found that only about one in three public high school biology teachers presented evolution consistently with the recommendations of the nation’s leading scientific authorities. And about 13% of the teachers emphasized to their students that creationism was a valid scientific alternative to modern evolutionary biology. In this paper, we investigate how the quality of evolution teaching, as measured by teachers’ reports of their teaching practices with regard to evolution and creationism, has changed in the intervening 12 years.

Results
We find substantial reductions in overtly creationist instruction and in the number of teachers who send mixed messages that legitimate creationism as a valid scientific alternative to evolutionary biology. We also report a substantial increase in the time that high school teachers devote to human evolution and general evolutionary processes. We show that these changes reflect both generational replacement—from teachers who are new to the profession—and changes in teaching practices among those who were teaching in the pre-Kitzmiller era.

Conclusion
Adoption of the Next Generation Science Standards, along with improvements in pre-service teacher education and in-service teacher professional development, appears to have contributed to a large reduction in both creationist instruction and mixed messages that could lead students to think that creationism is a scientific perspective. Combined with teachers devoting more hours to evolution—including human evolution—instruction at the high school level has improved by these measures since the last national survey in 2007.

so yes, there likely are still many places where evolution isn't taught, but we're getting better.