diff --git a/backend/alembic/versions/0004_bookmarks.py b/backend/alembic/versions/0004_bookmarks.py
new file mode 100644
index 0000000..436add5
--- /dev/null
+++ b/backend/alembic/versions/0004_bookmarks.py
@@ -0,0 +1,45 @@
+"""bookmark: saved locations
+
+Adds the ``bookmark`` table backing the "bookmarked locations" feature — one row
+per (user, grid cell), following the same shape as ``subscription``.
+
+Conditional on purpose, like 0003_user_discord_only: revision 0001 builds the
+schema from the *current* models.py via ``Base.metadata.create_all``, so a
+database created after ``Bookmark`` was added to the ORM (fresh envs, most tests)
+already has the table, and an unconditional ``create_table`` would fail there
+with a duplicate-table error. Only a database stamped before this revision is
+missing it.
+
+Revision ID: 0004_bookmarks
+Revises: 0003_user_discord_only
+Create Date: 2026-07-26
+"""
+import sqlalchemy as sa
+from alembic import op
+
+revision = "0004_bookmarks"
+down_revision = "0003_user_discord_only"
+branch_labels = None
+depends_on = None
+
+
+def _has_table() -> bool:
+    return sa.inspect(op.get_bind()).has_table("bookmark")
+
+
+def upgrade() -> None:
+    if _has_table():
+        return
+    # Built from the live ORM table (accounts.models.Bookmark) rather than
+    # hand-duplicated column definitions, so this can never drift from models.py.
+    from accounts.models import Bookmark
+
+    Bookmark.__table__.create(bind=op.get_bind())
+
+
+def downgrade() -> None:
+    if not _has_table():
+        return
+    from accounts.models import Bookmark
+
+    Bookmark.__table__.drop(bind=op.get_bind())