diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index fb68c00e7..632b9feac 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -100,6 +100,9 @@ jobs:
       - name: Run tests
         # --cov-fail-under is set here rather than in pyproject so that running a
         # single test file locally does not fail on the whole-project total.
+        # --ignore=tests/transfers excludes the deprecated NM_Aquifer / NM_Wells
+        # transfer tests; those scripts are frozen and run by hand against SQL
+        # Server, so they must not gate a pull request. See transfers/README.md.
         run: uv run pytest -vv --durations=20 --cov --cov-report=xml --cov-report=html --cov-report=term-missing --cov-fail-under="$COVERAGE_FAIL_UNDER" --junitxml=junit.xml --ignore=tests/transfers
 
       - name: Write coverage summary
diff --git a/CLAUDE.md b/CLAUDE.md
index 30549235f..147bab3d3 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -77,9 +77,15 @@ POSTGRES_PASSWORD=<password>
 ```
 
 ### Data Migration
+Both legacy transfer drivers are **deprecated** (see `transfers/README.md`); they
+raise `DeprecationWarning` and take no new migrations, but stay runnable for
+backfills.
 ```bash
-# Transfer data from legacy AMPAPI (NM_Aquifer) to new schema
+# NM_Aquifer (AMPAPI) -> new schema. Deprecated.
 python -m transfers.transfer
+
+# NM_Wells (geothermal) Phase-1 staging mirror. Deprecated.
+python -m transfers.transfer_geothermal
 ```
 
 ## Architecture
@@ -285,6 +291,24 @@ GitHub Actions workflows (`.github/workflows/`):
 
 ## Legacy System Migration
 
+**Deprecated.** Both legacy drivers are frozen -- `transfers/transfer.py`
+(NM_Aquifer/AMPAPI) and `transfers/transfer_geothermal.py` (NM_Wells, with
+`nmw_mirror_transfer.py`, `nmw_sql_dump.py`, `export_nmw_csvs.py`). Entry points
+raise `DeprecationWarning`. Do not add new migrations to either. They remain
+runnable because live API routes still read the `NMA_*` and `NMW_*` tables.
+Read **`transfers/README.md`** before touching this layer.
+
+Their tests live in `tests/transfers/` and **do not gate CI** --
+`.github/workflows/tests.yml` runs pytest with `--ignore=tests/transfers`, and
+`transfers/*` is omitted from coverage in `pyproject.toml`. Run them by hand:
+`uv run pytest tests/transfers`. Tests for the `NMA_*`/`NMW_*` ORM models
+(`db/nma_legacy.py`, `db/nmw_legacy.py`) stay in `tests/` proper and still gate
+CI, since live routes depend on those models.
+
+Still live, *not* deprecated: `services/scoped_transfer.py` and the
+`oco scoped-transfer` command, which import the individual NM_Aquifer
+transferers directly.
+
 **Source**: AMPAPI (SQL Server, `NM_Aquifer` schema)
 **Target**: OcotilloAPI (PostgreSQL + PostGIS)
 
diff --git a/SPEC.md b/SPEC.md
index 3731fa02e..727c3ade7 100644
--- a/SPEC.md
+++ b/SPEC.md
@@ -61,7 +61,7 @@ T8|x|export_nmw_csvs.py pymssql export|I.export
 T9|x|transfer_geothermal.py orchestrator|I.cli
 T10|x|6 OGC collections in pygeoapi-config.yml|V6,I.ogc
 T11|x|FK enforced via migration op.create_foreign_key; model index-only (resolved)|V2,V10
-T12|x|add NMW_* mirror/loader/migration/OGC tests (tests/test_nmw_mirror.py, 19 tests); found+fixed CAST-unwrap bug B1|V1,V2,V3,V5,V6,V10,V11
+T12|x|add NMW_* mirror/loader/migration/OGC tests (tests/transfers/test_nmw_mirror.py, 19 tests); found+fixed CAST-unwrap bug B1|V1,V2,V3,V5,V6,V10,V11
 T13|.|verify alembic down path drops all views+tables (V3) on real db|V3
 T14|.|run end-to-end load vs real dump, capture row counts per table|V2,V4
 T15|.|finish PR #738 body (truncated at "- I ") + reviewer notes|-
diff --git a/docs/nm_wells-migration.md b/docs/nm_wells-migration.md
index 35f335b5d..16cd97c6b 100644
--- a/docs/nm_wells-migration.md
+++ b/docs/nm_wells-migration.md
@@ -1,5 +1,10 @@
 # NM_Wells → Ocotillo migration
 
+> **Deprecated.** The Phase-1 loader described here is frozen and Phase 2 is not
+> being pursued through this path; see [transfers/README.md](../transfers/README.md).
+> Retained as the design record for the `NMW_*` mirror tables, which live API
+> routes still read.
+
 Migration of the legacy **NM_Wells** SQL Server database (and the related
 Subsurface Library) into OcotilloAPI. Source of truth for table inventory and
 field-level recommendations: `NM_Wells + Subsurface library.xlsx` (planning
diff --git a/docs/nm_wells-transfer-runbook.md b/docs/nm_wells-transfer-runbook.md
index 60731a8b5..9a78fea33 100644
--- a/docs/nm_wells-transfer-runbook.md
+++ b/docs/nm_wells-transfer-runbook.md
@@ -1,5 +1,12 @@
 # NM_Wells 1:1 Mirror Transfer — Runbook
 
+> **Deprecated.** The NM_Wells transfer path is frozen: no new migrations, no new
+> features, and its tests no longer gate CI (they live in `tests/transfers/`,
+> which `.github/workflows/tests.yml` ignores). The steps below stay accurate and
+> the code stays runnable, because the `NMW_*` tables are still read by live API
+> routes and so backfills and re-runs must remain possible. See
+> [transfers/README.md](../transfers/README.md).
+
 Operational steps to run the NM_Wells (geothermal) Phase-1 mirror transfer and verify it
 worked. Phase 1 is a faithful, column-for-column copy of the legacy NM_Wells SQL Server
 tables into the Postgres `NMW_*` staging mirror — no transform to the Ocotillo model.
@@ -225,8 +232,8 @@ psql "$DATABASE_URL" -c '\dv ogc_*'     # expect 0
 alembic upgrade head                     # recreate
 ```
 
-Automated coverage for this lives in `tests/test_nmw_mirror.py` (19 tests):
-`uv run pytest tests/test_nmw_mirror.py`.
+Automated coverage for this lives in `tests/transfers/test_nmw_mirror.py` (19 tests):
+`uv run pytest tests/transfers/test_nmw_mirror.py`.
 
 ---
 
diff --git a/tests/README.md b/tests/README.md
index 2593c5930..402c4c6de 100644
--- a/tests/README.md
+++ b/tests/README.md
@@ -6,7 +6,7 @@ This directory contains automated tests (unit, integration, transfer, and API be
 
 - `tests/unit/`: focused unit tests
 - `tests/integration/`: cross-component tests
-- `tests/transfers/`: transfer-focused tests
+- `tests/transfers/`: transfer-focused tests for the deprecated `transfers/` scripts; excluded from CI (see `tests/transfers/README.md`)
 - `tests/features/`: BDD-style feature tests
 
 ## Running tests
diff --git a/tests/transfers/README.md b/tests/transfers/README.md
new file mode 100644
index 000000000..e93578e83
--- /dev/null
+++ b/tests/transfers/README.md
@@ -0,0 +1,24 @@
+# Transfer tests
+
+Tests for the legacy migration scripts in `transfers/` — the deprecated
+NM_Aquifer (AMPAPI) and NM_Wells drivers.
+
+## Excluded from CI
+
+`.github/workflows/tests.yml` runs pytest with `--ignore=tests/transfers`, so
+nothing in this directory gates a pull request. The transfer scripts they cover
+are deprecated and run by hand against SQL Server; `transfers/*` is likewise
+omitted from the coverage total in `pyproject.toml`.
+
+Put new tests here only if they exercise `transfers/`. Tests for the
+`NMA_*`/`NMW_*` ORM models (`db/nma_legacy.py`, `db/nmw_legacy.py`) belong in
+`tests/` proper — those tables are still read by live API routes, so they stay
+in CI.
+
+## Running them
+
+From the repo root, against the `ocotilloapi_test` database:
+
+```bash
+uv run pytest tests/transfers
+```
diff --git a/tests/unit/test_contact_transfer_email_utils.py b/tests/transfers/test_contact_transfer_email_utils.py
similarity index 100%
rename from tests/unit/test_contact_transfer_email_utils.py
rename to tests/transfers/test_contact_transfer_email_utils.py
diff --git a/tests/test_minor_trace_chemistry_transfer.py b/tests/transfers/test_minor_trace_chemistry_transfer.py
similarity index 100%
rename from tests/test_minor_trace_chemistry_transfer.py
rename to tests/transfers/test_minor_trace_chemistry_transfer.py
diff --git a/tests/test_nmw_mirror.py b/tests/transfers/test_nmw_mirror.py
similarity index 99%
rename from tests/test_nmw_mirror.py
rename to tests/transfers/test_nmw_mirror.py
index 4de183fe4..30552f734 100644
--- a/tests/test_nmw_mirror.py
+++ b/tests/transfers/test_nmw_mirror.py
@@ -38,7 +38,7 @@
 from transfers.nmw_mirror_transfer import NMW_MIRROR_SPECS
 from transfers.nmw_sql_dump import _parse_value, iter_table_rows
 
-ROOT = os.path.dirname(os.path.dirname(__file__))
+ROOT = os.path.dirname(os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
 
 # DB relations created by the OGC-view migrations (d1e2f3a4b5c6, e2f3a4b5c6d7).
 OGC_VIEWS = [
diff --git a/tests/test_sensor_transfer.py b/tests/transfers/test_sensor_transfer.py
similarity index 100%
rename from tests/test_sensor_transfer.py
rename to tests/transfers/test_sensor_transfer.py
diff --git a/tests/test_thing_transfer.py b/tests/transfers/test_thing_transfer.py
similarity index 100%
rename from tests/test_thing_transfer.py
rename to tests/transfers/test_thing_transfer.py
diff --git a/tests/test_transfer_legacy_dates.py b/tests/transfers/test_transfer_legacy_dates.py
similarity index 100%
rename from tests/test_transfer_legacy_dates.py
rename to tests/transfers/test_transfer_legacy_dates.py
diff --git a/tests/test_well_transfer.py b/tests/transfers/test_well_transfer.py
similarity index 100%
rename from tests/test_well_transfer.py
rename to tests/transfers/test_well_transfer.py
diff --git a/transfers/README.md b/transfers/README.md
index 08e032349..2bac5b0b1 100644
--- a/transfers/README.md
+++ b/transfers/README.md
@@ -2,9 +2,35 @@
 
 This directory contains legacy-to-target ETL transfer logic.
 
+## Status: deprecated
+
+Both legacy migration drivers are frozen. Do not add new migrations to either:
+
+- `transfers/transfer.py` -- the NM_Aquifer (AMPAPI, SQL Server) driver.
+- `transfers/transfer_geothermal.py` -- the NM_Wells (geothermal) driver, plus
+  its `nmw_mirror_transfer.py`, `nmw_sql_dump.py`, and `export_nmw_csvs.py`
+  supporting modules.
+
+Their top-level entry points raise `DeprecationWarning`. They are kept runnable
+because the tables they populate (`NMA_*`, `NMW_*`) are still read by live API
+routes, so backfills and re-runs must remain possible -- but they receive no new
+features.
+
+Consequently their tests live in `tests/transfers/` and do **not** gate CI
+(`.github/workflows/tests.yml` runs pytest with `--ignore=tests/transfers`), and
+`transfers/*` is omitted from the coverage total in `pyproject.toml`. Run them by
+hand with `uv run pytest tests/transfers`.
+
+Still live and *not* deprecated:
+
+- `services/scoped_transfer.py` and the `oco scoped-transfer` command, which
+  import the individual NM_Aquifer transferers directly.
+- `transfers/seed_geothermal.py`, a dev/test seeder that generates fake data
+  rather than reading a legacy source.
+
 ## Main orchestration
 
-- `transfers/transfer.py`
+- `transfers/transfer.py` (deprecated)
 
 ## Important supporting modules
 
diff --git a/transfers/export_nmw_csvs.py b/transfers/export_nmw_csvs.py
index 51daf403e..6ee6cc106 100644
--- a/transfers/export_nmw_csvs.py
+++ b/transfers/export_nmw_csvs.py
@@ -1,4 +1,8 @@
-"""Export NM_Wells SQL Server tables to CSV files for the transfer pipeline.
+"""DEPRECATED: export NM_Wells SQL Server tables to CSV for the transfer pipeline.
+
+Part of the frozen NM_Wells migration path; see the deprecation note in
+``transfers/transfer_geothermal.py``. Kept runnable for re-exports, but it gets
+no new features and its tests no longer gate CI.
 
 Connects to the NM_Wells SQL Server database and exports each source table to
 transfers/data/nma_csv_cache/<table>.csv, which is where nmw_mirror_transfer.py
@@ -16,6 +20,7 @@
 """
 
 import os
+import warnings
 from pathlib import Path
 
 import pymssql
@@ -64,6 +69,12 @@ def export_table(cursor, table: str, out_path: Path) -> int:
 
 
 def main():
+    warnings.warn(
+        "transfers.export_nmw_csvs is deprecated; the NM_Wells migration path "
+        "is frozen and receives no new migrations.",
+        DeprecationWarning,
+        stacklevel=2,
+    )
     OUT_DIR.mkdir(parents=True, exist_ok=True)
     print(
         f"Connecting to {os.environ.get('NMW_HOST')} / {os.environ.get('NMW_DATABASE', 'NM_Wells')}"
diff --git a/transfers/nmw_mirror_transfer.py b/transfers/nmw_mirror_transfer.py
index d59ef4eaf..1d42fef6c 100644
--- a/transfers/nmw_mirror_transfer.py
+++ b/transfers/nmw_mirror_transfer.py
@@ -13,7 +13,12 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 # ===============================================================================
-"""Load the NM_Wells SQL dump into the ``NMW_*`` 1:1 staging mirror tables.
+"""DEPRECATED: load the NM_Wells SQL dump into the ``NMW_*`` staging mirror.
+
+Part of the frozen NM_Wells migration path; see the deprecation note in
+``transfers/transfer_geothermal.py``. The ``NMW_*`` tables it populates are
+still read by live API routes, so this loader stays runnable for backfills and
+re-runs, but it gets no new features and its tests no longer gate CI.
 
 Phase 1 of the NM_Wells migration (see db/nmw_legacy.py and
 docs/nm_wells-migration.md). This is a faithful copy: each source table's CSV
@@ -47,6 +52,7 @@
 import os
 import tempfile
 import uuid
+import warnings
 from dataclasses import dataclass
 
 import pandas as pd
@@ -317,6 +323,12 @@ def transfer_nmw_mirror(session: Session, limit: int = None) -> tuple:
     ``(session, limit)`` signature as the other session-based transfers. Returns
     ``(num_tables_loaded, total_rows_inserted, errors)``.
     """
+    warnings.warn(
+        "transfers.nmw_mirror_transfer is deprecated; the NM_Wells migration "
+        "path is frozen and receives no new migrations.",
+        DeprecationWarning,
+        stacklevel=2,
+    )
     limit = int(limit or 0)
     dump = os.getenv(_SQL_DUMP_ENV)
     out_dir = None
diff --git a/transfers/nmw_sql_dump.py b/transfers/nmw_sql_dump.py
index f7010b849..e0b758539 100644
--- a/transfers/nmw_sql_dump.py
+++ b/transfers/nmw_sql_dump.py
@@ -13,7 +13,11 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 # ===============================================================================
-"""Parse a SQL Server data-dump ``.sql`` file into per-table CSVs.
+"""DEPRECATED: parse a SQL Server data-dump ``.sql`` file into per-table CSVs.
+
+Part of the frozen NM_Wells migration path; see the deprecation note in
+``transfers/transfer_geothermal.py``. Kept runnable for re-runs of the NM_Wells
+dump load, but it gets no new features and its tests no longer gate CI.
 
 ``INSERT [dbo].[<table>] (<cols>) VALUES (<vals>)[, (<vals>) ...]`` statements
 (SSMS "Generate Scripts -> data" / bcp INSERT mode) are split with ``sqlparse``
diff --git a/transfers/transfer_geothermal.py b/transfers/transfer_geothermal.py
index 6945ea01d..5071d32aa 100644
--- a/transfers/transfer_geothermal.py
+++ b/transfers/transfer_geothermal.py
@@ -13,10 +13,15 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 # ===============================================================================
-"""Standalone orchestrator for the NM_Wells (geothermal) migration.
+"""DEPRECATED: standalone orchestrator for the NM_Wells (geothermal) migration.
 
-Separate from the deprecated ``transfers/transfer.py`` (NM_Aquifer driver). This
-script runs the NM_Wells Phase-1 staging migration:
+Deprecated alongside ``transfers/transfer.py`` (the NM_Aquifer driver): both
+legacy migration drivers are frozen. Do not add new migrations here. The
+``NMW_*`` staging tables this loads remain in service -- live API routes still
+read them -- so the loader is kept runnable for backfills and re-runs, but it
+gets no new features and its tests no longer gate CI.
+
+This script runs the NM_Wells Phase-1 staging migration:
 
 1. Reference -> lexicon load (``ref_*`` lookups), gated by
    ``TRANSFER_GEOTHERMAL_REFERENCE`` (default True).
@@ -37,6 +42,7 @@
 """
 
 import os
+import warnings
 
 from dotenv import load_dotenv
 
@@ -63,6 +69,12 @@
 
 def run_geothermal_transfer(limit: int = None) -> dict:
     """Run the NM_Wells geothermal staging migration. Returns a summary dict."""
+    warnings.warn(
+        "transfers.transfer_geothermal is deprecated; the NM_Wells migration "
+        "drivers are frozen and receive no new migrations.",
+        DeprecationWarning,
+        stacklevel=2,
+    )
     limit = int(limit if limit is not None else os.getenv("TRANSFER_LIMIT", 0) or 0)
     summary: dict = {}