Check the website of The Association of Collegiate Schools of Planning: http://www.acsp.org/education_guide/schools
The website has a directory of undergraduate and graduate programs.
A surprising number of schools offer an undergraduate major in planning. Still, it is often seen primarily as a major to be pursued at the graduate level. Students can enter graduate programs in planning from a variety of undergraduate majors. Often, students with an interest in it as undergraduates can find relevant programs in geography departments or in interdisciplinary urban studies programs.
Almost every planner I know has a graduate degree and very few have a bachelors in urban planning. You can major in anything going into a graduate planning program: mine were in math and design, friends had majored in political science, sociology, religious studies, civil engineering, art history, linguistics, hotel management and a surprising number with a previously obtained law degree.
Cal poly SLO has an undergrad in that. But the ppl I know who worked in that area and related had degrees from Hampshire and did a sr year project, univ Iowa with grad at uva, unc-ch, Berkeley…