diff --git a/flopy4/mf6/codec/reader/grammar/__init__.py b/flopy4/mf6/codec/reader/grammar/__init__.py
index a7bf0e34..d6e7e6b3 100644
--- a/flopy4/mf6/codec/reader/grammar/__init__.py
+++ b/flopy4/mf6/codec/reader/grammar/__init__.py
@@ -17,6 +17,7 @@ def _get_template_env():
     )
     env.filters["field_type"] = filters.field_type
     env.filters["record_child_type"] = filters.record_child_type
+    env.filters["to_rule_name"] = filters.to_rule_name
     return env
 
 
diff --git a/flopy4/mf6/codec/reader/grammar/filters.py b/flopy4/mf6/codec/reader/grammar/filters.py
index 7ff0c795..c43bffa1 100644
--- a/flopy4/mf6/codec/reader/grammar/filters.py
+++ b/flopy4/mf6/codec/reader/grammar/filters.py
@@ -77,3 +77,11 @@ def get_recarray_name(block_name: str) -> str:
     if block_name == "period":
         return "stress_period_data"
     return f"{block_name}data"
+
+
+def to_rule_name(name: str) -> str:
+    """Convert a field name to a valid Lark rule name.
+
+    Lark rule names must not contain hyphens, so we replace them with underscores.
+    """
+    return name.replace("-", "_")
diff --git a/flopy4/mf6/codec/reader/grammar/generated/gwf-sto.lark b/flopy4/mf6/codec/reader/grammar/generated/gwf-sto.lark
index 073513a4..84de23c8 100644
--- a/flopy4/mf6/codec/reader/grammar/generated/gwf-sto.lark
+++ b/flopy4/mf6/codec/reader/grammar/generated/gwf-sto.lark
@@ -22,7 +22,7 @@ period_block: "begin"i "period"i block_index period_fields "end"i "period"i bloc
 block_index: integer
 options_fields: (save_flows | storagecoefficient | ss_confined_only | tvs_filerecord | export_array_ascii | export_array_netcdf | dev_original_specific_storage | dev_oldstorageformulation)*
 griddata_fields: (iconvert | ss | sy)*
-period_fields: (steady-state | transient)*
+period_fields: (steady_state | transient)*
 save_flows: "save_flows"i 
 storagecoefficient: "storagecoefficient"i 
 ss_confined_only: "ss_confined_only"i 
@@ -34,5 +34,5 @@ dev_oldstorageformulation: "dev_oldstorageformulation"i
 iconvert: "iconvert"i array
 ss: "ss"i array
 sy: "sy"i array
-steady-state: "steady-state"i 
+steady_state: "steady-state"i 
 transient: "transient"i 
diff --git a/flopy4/mf6/codec/reader/grammar/templates/macros.jinja b/flopy4/mf6/codec/reader/grammar/templates/macros.jinja
index 6bf47c9b..5fe7163e 100644
--- a/flopy4/mf6/codec/reader/grammar/templates/macros.jinja
+++ b/flopy4/mf6/codec/reader/grammar/templates/macros.jinja
@@ -1,12 +1,12 @@
 {# Field rendering macros #}
 
 {% macro record_field(field_name, field) -%}
-{{ field_name }}: {% for child_name, child in field.children.items() -%}
+{{ field_name|to_rule_name }}: {% for child_name, child in field.children.items() -%}
 {%- set child_type = child|record_child_type -%}
 {%- if child.type == 'keyword' -%}
 "{{ child.name }}"i
 {%- elif child.type == 'union' -%}
-{{ child_name }}
+{{ child_name|to_rule_name }}
 {%- else -%}
 {{ child_type }}
 {%- endif -%}
@@ -15,12 +15,12 @@
 {%- endmacro %}
 
 {% macro union_field(field_name, field) -%}
-{{ field_name }}: {% for child_name, child in field.children.items() -%}
-{{ field_name }}_{{ child_name }}
+{{ field_name|to_rule_name }}: {% for child_name, child in field.children.items() -%}
+{{ field_name|to_rule_name }}_{{ child_name|to_rule_name }}
 {%- if not loop.last %} | {% endif -%}
 {%- endfor %}
 {% for child_name, child in field.children.items() -%}
-{{ field_name }}_{{ child_name }}: {% if child.type == 'keyword' -%}
+{{ field_name|to_rule_name }}_{{ child_name|to_rule_name }}: {% if child.type == 'keyword' -%}
 "{{ child.name }}"i
 {%- else -%}
 "{{ child.name }}"i {{ child.type }}
@@ -29,17 +29,17 @@
 {%- endmacro %}
 
 {% macro simple_field(field_name, field, field_type) -%}
-{{ field_name }}: "{{ field.name }}"i {{ field_type }}
+{{ field_name|to_rule_name }}: "{{ field.name }}"i {{ field_type }}
 {%- endmacro %}
 
 {% macro nested_union(child_name, child) -%}
-{{ child_name }}: {% for opt_name, opt in child.children.items() -%}
-{{ child_name }}_{{ opt_name }}
+{{ child_name|to_rule_name }}: {% for opt_name, opt in child.children.items() -%}
+{{ child_name|to_rule_name }}_{{ opt_name|to_rule_name }}
 {%- if not loop.last %} | {% endif -%}
 {%- endfor %}
 
 {% for opt_name, opt in child.children.items() -%}
-{{ child_name }}_{{ opt_name }}: {% if opt.type == 'keyword' -%}
+{{ child_name|to_rule_name }}_{{ opt_name|to_rule_name }}: {% if opt.type == 'keyword' -%}
 "{{ opt.name }}"i
 {%- else -%}
 "{{ opt.name }}"i {{ opt.type }}{% if opt.shape %}+{% endif %}
@@ -61,12 +61,12 @@
 {%- macro field_list(block_name, fields, recarray_name) -%}
 {%- if recarray_name -%}
 {{ block_name }}_fields: (
-{%- for field_name in fields %}{{ field_name }} | {% endfor -%}
+{%- for field_name in fields %}{{ field_name|to_rule_name }} | {% endfor -%}
 {{ recarray_name }})*
 {%- else -%}
 {{ block_name }}_fields: (
 {%- for field_name in fields %}
-{{- field_name }}{% if not loop.last %} | {% endif %}
+{{- field_name|to_rule_name }}{% if not loop.last %} | {% endif %}
 {%- endfor -%}
 )*
 {%- endif -%}
diff --git a/flopy4/mf6/codec/reader/transformer.py b/flopy4/mf6/codec/reader/transformer.py
index 2aa1e101..102e17a4 100644
--- a/flopy4/mf6/codec/reader/transformer.py
+++ b/flopy4/mf6/codec/reader/transformer.py
@@ -24,6 +24,14 @@ class BasicTransformer(Transformer):
     grammar. Yields blocks simply as collections of lines of tokens.
     """
 
+    def __getattr__(self, name):
+        """Handle typed__ prefixed methods by delegating to the unprefixed version."""
+        if name.startswith("typed__"):
+            unprefixed = name[7:]  # Remove "typed__" prefix
+            if hasattr(self, unprefixed):
+                return getattr(self, unprefixed)
+        raise AttributeError(f"'{type(self).__name__}' object has no attribute '{name}'")
+
     def start(self, items: list[Any]) -> dict[str, Any]:
         blocks = {}
         for item in items:
@@ -72,6 +80,14 @@ def __init__(self, visit_tokens=False, dfn: Dfn = None):
         # Create a flattened fields dict that includes nested fields
         self._flat_fields = self._flatten_fields(self.fields) if self.fields else None
 
+    def __getattr__(self, name):
+        """Handle typed__ prefixed methods by delegating to the unprefixed version."""
+        if name.startswith("typed__"):
+            unprefixed = name[7:]  # Remove "typed__" prefix
+            if hasattr(self, unprefixed):
+                return getattr(self, unprefixed)
+        raise AttributeError(f"'{type(self).__name__}' object has no attribute '{name}'")
+
     def _flatten_fields(self, fields: dict) -> dict:
         """Recursively flatten fields dict to include children of records and unions."""
         flat = dict(fields)  # Start with top-level fields
@@ -181,7 +197,13 @@ def filename(self, items: list[Any]) -> Path:
         return Path(items[0].strip("\"'"))
 
     def string(self, items: list[Any]) -> str:
-        return items[0].strip("\"'")
+        # String can be either a token or a tree (word)
+        value = items[0]
+        if hasattr(value, "strip"):
+            return value.strip("\"'")
+        else:
+            # It's a tree, extract the token value
+            return str(value.children[0]) if hasattr(value, "children") else str(value)
 
     def simple_string(self, items: list[Any]) -> str:
         """Handle simple string (unquoted word or escaped string)."""
@@ -321,7 +343,12 @@ def __default__(self, data, children, meta):
                     else:
                         # Non-keyword alternatives return the transformed children
                         return children[0] if len(children) == 1 else children
-        if (field := self._flat_fields.get(data, None)) is not None:
+        # Try to find the field, checking with underscore replacement for hyphens
+        field = self._flat_fields.get(data, None)
+        if field is None and "-" in data:
+            # Try with hyphens instead of underscores (reverse of to_rule_name)
+            field = self._flat_fields.get(data.replace("_", "-"), None)
+        if field is not None:
             if field.type == "keyword":
                 return data, True
             elif field.type == "record" and hasattr(field, "children") and field.children:
diff --git a/test/test_mf6_reader.py b/test/test_mf6_reader.py
index 8e29d8e6..e1614d00 100644
--- a/test/test_mf6_reader.py
+++ b/test/test_mf6_reader.py
@@ -7,7 +7,7 @@
 import pytest
 import xarray as xr
 from lark import Lark
-from modflow_devtools.dfn import Dfn, load_flat
+from modflow_devtools.dfn import Dfn, MapV1To2, load_flat
 from modflow_devtools.models import get_models
 from packaging.version import Version
 
@@ -417,9 +417,15 @@ def test_transform_gwf_ic_file(model_workspace, dfn_path):
     assert "griddata" in result  # IC has griddata block
     assert "strt" in result["griddata"]  # Starting heads
 
-    # Check strt field exists (array transformation not fully implemented yet)
-    strt_data = result["griddata"]["strt"]
-    assert strt_data is not None
+    # Check strt array structure
+    strt = result["griddata"]["strt"]
+    assert "control" in strt
+    assert "data" in strt
+    assert strt["control"]["type"] in ["constant", "internal", "external"]
+
+    # If internal or constant, should have data
+    if strt["control"]["type"] in ["constant", "internal"]:
+        assert strt["data"] is not None
 
 
 @pytest.mark.parametrize("model_workspace", ["mf6/example/ex-gwf-bcf2ss-p01a"], indirect=True)
@@ -568,3 +574,142 @@ def test_transform_gwf_oc_file(model_workspace, dfn_path):
     for rec in save_records:
         assert "ocsetting" in rec
         assert rec["ocsetting"] == "all"
+
+
+@pytest.mark.parametrize("model_workspace", ["mf6/example/ex-gwf-csub-p01"], indirect=True)
+def test_transform_gwf_dis_file(model_workspace, dfn_path):
+    """Test transforming a parsed GWF DIS file into structured data."""
+
+    # Load the DFN for DIS and convert to V2
+    v1_dfns = load_flat(dfn_path)
+    mapper = MapV1To2()
+    dis_dfn = mapper.map(v1_dfns["gwf-dis"])
+
+    # Find the DIS file
+    dis_files = list(model_workspace.rglob("*.dis"))
+    assert len(dis_files) > 0
+
+    dis_file = dis_files[0]
+    parser = get_typed_parser("gwf-dis")
+    transformer = TypedTransformer(dfn=dis_dfn)
+
+    # Read, parse, and transform
+    with open(dis_file, "r") as f:
+        content = f.read()
+
+    tree = parser.parse(content)
+    result = transformer.transform(tree)
+
+    # Check structure
+    assert isinstance(result, dict)
+
+    # Check dimensions block
+    assert "dimensions" in result
+    assert "nlay" in result["dimensions"]
+    assert "nrow" in result["dimensions"]
+    assert "ncol" in result["dimensions"]
+    assert result["dimensions"]["nlay"] > 0
+    assert result["dimensions"]["nrow"] > 0
+    assert result["dimensions"]["ncol"] > 0
+
+    # Check griddata block
+    assert "griddata" in result
+    griddata = result["griddata"]
+    assert "delr" in griddata
+    assert "delc" in griddata
+    assert "top" in griddata
+    assert "botm" in griddata
+
+    # Each array should have control and data
+    assert "control" in griddata["delr"]
+    assert "data" in griddata["delr"]
+
+
+@pytest.mark.parametrize("model_workspace", ["mf6/example/ex-gwf-csub-p01"], indirect=True)
+def test_transform_gwf_npf_file(model_workspace, dfn_path):
+    """Test transforming a parsed GWF NPF file into structured data."""
+
+    # Load the DFN for NPF and convert to V2
+    v1_dfns = load_flat(dfn_path)
+    mapper = MapV1To2()
+    npf_dfn = mapper.map(v1_dfns["gwf-npf"])
+
+    # Find the NPF file
+    npf_files = list(model_workspace.rglob("*.npf"))
+    assert len(npf_files) > 0
+
+    npf_file = npf_files[0]
+    parser = get_typed_parser("gwf-npf")
+    transformer = TypedTransformer(dfn=npf_dfn)
+
+    # Read, parse, and transform
+    with open(npf_file, "r") as f:
+        content = f.read()
+
+    tree = parser.parse(content)
+    result = transformer.transform(tree)
+
+    # Check structure
+    assert isinstance(result, dict)
+
+    # Check options block
+    assert "options" in result
+    options = result["options"]
+
+    # Should have save_specific_discharge option
+    assert "save_specific_discharge" in options
+    assert options["save_specific_discharge"] is True
+
+    # Check griddata block
+    assert "griddata" in result
+    griddata = result["griddata"]
+
+    # NPF should have at least icelltype and k
+    assert "icelltype" in griddata
+    assert "k" in griddata
+
+    # Each array should have control and data
+    assert "control" in griddata["icelltype"]
+    assert "data" in griddata["icelltype"]
+    assert "control" in griddata["k"]
+    assert "data" in griddata["k"]
+
+
+@pytest.mark.parametrize("model_workspace", ["mf6/example/ex-gwf-csub-p01"], indirect=True)
+def test_transform_gwf_sto_file(model_workspace, dfn_path):
+    """Test transforming a parsed GWF STO file into structured data."""
+
+    # Load the DFN for STO and convert to V2
+    v1_dfns = load_flat(dfn_path)
+    mapper = MapV1To2()
+    sto_dfn = mapper.map(v1_dfns["gwf-sto"])
+
+    # Find the STO file
+    sto_files = list(model_workspace.rglob("*.sto"))
+
+    # Skip if no STO files (not all models have storage)
+    if len(sto_files) == 0:
+        pytest.skip("No STO files found in this model")
+
+    sto_file = sto_files[0]
+    parser = get_typed_parser("gwf-sto")
+    transformer = TypedTransformer(dfn=sto_dfn)
+
+    # Read, parse, and transform
+    with open(sto_file, "r") as f:
+        content = f.read()
+
+    tree = parser.parse(content)
+    result = transformer.transform(tree)
+
+    # Check structure
+    assert isinstance(result, dict)
+
+    # Check griddata block
+    assert "griddata" in result
+    griddata = result["griddata"]
+
+    # STO should have iconvert
+    assert "iconvert" in griddata
+    assert "control" in griddata["iconvert"]
+    assert "data" in griddata["iconvert"]