HELENA -- Montana's 2006 graduating high school students scored higher on the ACT college entrance exam than in previous years and continued to score higher than the national average, results released Wednesday show.

The average score for Montana students was 21.9, compared with 21.1 nationwide. Last year, Montana students had an average score of 21.8. ACT scores range from 1 to 36.

Montana students scored higher than the national average in all four categories tested: English, mathematics, reading and science. More than 6,000 Montana students -- or 57 percent of graduating seniors in both public and private schools -- took the test.

''The current ACT results again speak well of the quality of education being provided by Montana's teachers and the support our students receive at home and in their communities,'' said Linda McCulloch, the state's superintendent of public instruction.

Only 12 states had higher composite scores than Montana, but in many of those states, only a small percentage of students took the test. Those are usually the state's top students, McCulloch said.

''If you eliminate all those tiny percentages, you've got us at about fourth, which isn't bad at all,'' McCulloch said. ''But that's not saying we still don't have room for improvement.''

One area of concern is math and science scores. The results indicate that about half the students who took the test may not be ready for college freshman-level math coursework, and more than half may not be ready for college freshman-level science coursework.

But McCulloch said the ACT test is just one indicator of how a student will do in college, and added that the results still show that Montana students are better-prepared for those classes than the national average.

''I think what this directly correlates to is the number of students who take college preparatory classes,'' McCulloch said, pointing to recent funding cuts that have led some high schools in the state to eliminate some of those classes.

''As budgets become tighter, you have to eliminate something, and you eliminate the things you aren't required by law or administrative rule to do,'' she said.

Another area of concern was the average composite score of 17.5 by American Indian students in Montana, which is well below the state average.

McCulloch pointed to all-day kindergarten classes as a way to reduce that gap, a plan she has been pushing. Also, she said the ongoing Indian Education for All program would help.

Girls in Montana scored slightly higher than boys on the test, with an average composite score of 21.9. That compares with 21.8 for boys.

Montana girls had higher scores in English and reading. Montana boys scored higher in math and science.

One Montana student scored a perfect 36 on the test, McCulloch said. The student's name and school were not available Tuesday night.