Among Western states, only Montana is losing more of its high school graduates than Idaho to colleges and universities in other states, a state Board of Education official says.

Jerry Engstrom, management information officer for the Office of the Board of Education, told board members recently that 21.1 percent of Idaho students entering college as freshmen go to other states.Neighboring Montana retains 77 percent of its high school graduates, Engstrom said, but all the other states in the West keep more students at home.

Oregon retains about 88 percent and Washington, Utah, Wyoming, California, Nevada and Arizona all keep more than 90 percent at home.

Engstrom said it is not necessarily bad to have Idaho high school graduates going to college in other states. "It's normal and even desirable to have students leaving the state and coming in," he said.

But since Idaho loses most of its students to institutions close to the state's borders, Engstrom said more attention probably should be paid to keeping those students in the state.

The student migration reports, which covered fall enrollment in 1986, said Idaho colleges and universities enrolled 6,124 first-time freshmen from Idaho and 3,117 from other states. The College of Idaho did not submit a report, Engstrom said.

But the figures are distorted by Ricks College, Engstrom said. The private, two-year college operated by The Church of Jesus Christ of Latter-day Saints at Rexburg had 2,366 out-of-state students, more than two-thirds of the state total. Washington, with 518; California, 388 and Oregon, 257, provided the bulk of the students coming from other states to attend college in Idaho, Engstrom said.

Of the 1,655 Idaho students leaving for other states, 287 enrolled at the main campus of Brigham Young University and another 22 at the BYU campus in Hawaii. Treasure Valley Community College in Ontario, Ore., attracted 149 students, Utah State University 115 and the University of Utah 57.