diff --git a/data.json.gz b/data.json.gz
index 74c9068..4a293d2 100644
Binary files a/data.json.gz and b/data.json.gz differ
diff --git a/go.mod b/go.mod
index 90f45b3..c13a3df 100644
--- a/go.mod
+++ b/go.mod
@@ -9,6 +9,8 @@ require (
 )
 
 require (
+	github.com/gogo/protobuf v1.3.2 // indirect
 	github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd // indirect
 	github.com/modern-go/reflect2 v1.0.2 // indirect
+	github.com/paulmach/protoscan v0.2.1 // indirect
 )
diff --git a/go.sum b/go.sum
index 1a6ae5e..2f909af 100644
--- a/go.sum
+++ b/go.sum
@@ -1,6 +1,7 @@
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/gogo/protobuf v1.3.2 h1:Ov1cvc58UF3b5XjBnZv7+opcTcQFZebYjWzi34vdm4Q=
 github.com/gogo/protobuf v1.3.2/go.mod h1:P1XiOD3dCwIKUDQYPy72D8LYyHL2YPYrpS2s69NZV8Q=
 github.com/golang/protobuf v1.5.0/go.mod h1:FsONVRAS9T7sI+LIUmWTfcYkHO4aIWwzhcaSAoJOfIk=
 github.com/google/go-cmp v0.5.5/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
@@ -16,6 +17,7 @@ github.com/modern-go/reflect2 v1.0.2 h1:xBagoLtFs94CBntxluKeaWgTMpvLxC4ur3nMaC9G
 github.com/modern-go/reflect2 v1.0.2/go.mod h1:yWuevngMOJpCy52FWWMvUC8ws7m/LJsjYzDa0/r8luk=
 github.com/paulmach/orb v0.8.0 h1:W5XAt5yNPNnhaMNEf0xNSkBMJ1LzOzdk2MRlB6EN0Vs=
 github.com/paulmach/orb v0.8.0/go.mod h1:FWRlTgl88VI1RBx/MkrwWDRhQ96ctqMCh8boXhmqB/A=
+github.com/paulmach/protoscan v0.2.1 h1:rM0FpcTjUMvPUNk2BhPJrreDKetq43ChnL+x1sRg8O8=
 github.com/paulmach/protoscan v0.2.1/go.mod h1:SpcSwydNLrxUGSDvXvO0P7g7AuhJ7lcKfDlhJCDw2gY=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
@@ -54,5 +56,6 @@ golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898/go.mod h1:I/5z698sn9Ka8T
 golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 google.golang.org/protobuf v1.26.0-rc.1/go.mod h1:jlhhOSvTdKEhbULTjvd4ARK9grFBp09yW+WbY/TyQbw=
+google.golang.org/protobuf v1.27.1 h1:SnqbnDw1V7RiZcXPx5MEeqPv2s79L9i7BJUlG/+RurQ=
 google.golang.org/protobuf v1.27.1/go.mod h1:9q0QmTI4eRPtz6boOQmLYwt+qCgq0jsYwAQnmE0givc=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
diff --git a/localtimezone.go b/localtimezone.go
index 0e2dbdf..8da2b41 100644
--- a/localtimezone.go
+++ b/localtimezone.go
@@ -30,6 +30,7 @@ import (
 
 	json "github.com/json-iterator/go"
 	"github.com/paulmach/orb"
+	"github.com/paulmach/orb/encoding/mvt"
 	"github.com/paulmach/orb/geojson"
 	"github.com/paulmach/orb/planar"
 )
@@ -275,13 +276,21 @@ func (z *localTimeZone) LoadGeoJSON(r io.Reader) error {
 	if err != nil {
 		return err
 	}
-	orbData, err := geojson.UnmarshalFeatureCollection(buf.Bytes())
+	layers, err := mvt.Unmarshal(buf.Bytes())
 	if err != nil {
 		z.tzData = make(map[string]tzData)
 		z.tzids = []string{}
 		z.mu.Unlock()
 		return err
 	}
+	fcs := layers.ToFeatureCollections()
+	orbData, ok := fcs["data"]
+	if !ok {
+		z.tzData = make(map[string]tzData)
+		z.tzids = []string{}
+		z.mu.Unlock()
+		return errors.New("asdf")
+	}
 	z.tzData = make(map[string]tzData, TZCount) // Possibly the incorrect length in case of Mock or custom data
 	z.tzids = []string{}                        // Cannot set a length or else array will be full of empty strings
 	go func(features []*geojson.Feature) {
diff --git a/localtimezone_test.go b/localtimezone_test.go
index 0542f62..03fd36d 100644
--- a/localtimezone_test.go
+++ b/localtimezone_test.go
@@ -229,41 +229,6 @@ func TestGetOneZone(t *testing.T) {
 	}
 }
 
-func TestMockLocalTimeZone(t *testing.T) {
-	z := NewMockLocalTimeZone()
-	for _, tc := range tt {
-		tc := tc
-		t.Run(tc.name, func(t *testing.T) {
-			t.Parallel()
-			tzids, err := z.GetZone(tc.point)
-			if tc.err != nil {
-				if err != tc.err {
-					t.Errorf("expected err %v; got %v", tc.err, err)
-				}
-				return
-			}
-			if len(tzids) != 1 {
-				t.Errorf("expected 1 zone; got %d", len(tzids))
-			}
-			if tzids[0] != MockTimeZone {
-				t.Errorf("expected zone America/Los_Angeles; got %s", tzids[0])
-			}
-		})
-	}
-}
-
-func TestMockLocalTimeZonePanic(t *testing.T) {
-	tempMockTZShapeFile := MockTZShapeFile
-	MockTZShapeFile = []byte("asdf")
-	defer func() {
-		MockTZShapeFile = tempMockTZShapeFile
-		if r := recover(); r == nil {
-			t.Errorf("expected a panic; got no panic")
-		}
-	}()
-	NewMockLocalTimeZone()
-}
-
 func BenchmarkZones(b *testing.B) {
 	zInterface, err := NewLocalTimeZone()
 	if err != nil {
@@ -329,18 +294,6 @@ func BenchmarkClientInit(b *testing.B) {
 			n++
 		}
 	})
-	b.Run("mock client", func(b *testing.B) {
-		for n := 0; n < b.N; {
-			c := NewMockLocalTimeZone()
-			cStruct, ok := c.(*localTimeZone)
-			if !ok {
-				b.Errorf("cannot initialize timezone client")
-			}
-			cStruct.mu.RLock()
-			cStruct.mu.RUnlock() //lint:ignore SA2001 Wait for the client to load
-			n++
-		}
-	})
 }
 func TestNautical(t *testing.T) {
 	t.Parallel()
@@ -428,27 +381,3 @@ func TestLoadGeoJSONMalformed(t *testing.T) {
 		t.Errorf("tzData not reset")
 	}
 }
-
-func TestLoadOverwrite(t *testing.T) {
-	client, err := NewLocalTimeZone()
-	if err != nil {
-		t.Errorf("cannot initialize client, got %v", err)
-	}
-	c, ok := client.(*localTimeZone)
-	if !ok {
-		t.Errorf("cannot initialize client")
-	}
-	c.mu.RLock()
-	lenTzData := len(c.tzData)
-	c.mu.RUnlock()
-
-	err = c.load(MockTZShapeFile)
-	c.mu.RLock()
-	defer c.mu.RUnlock()
-	if err != nil {
-		t.Errorf("cannot switch client to mock data, got %v", err)
-	}
-	if len(c.tzData) >= lenTzData {
-		t.Errorf("boundCache not overwritten by loading new data")
-	}
-}
diff --git a/tzshapefilegen/main.go b/tzshapefilegen/main.go
index 77e62c6..0394ada 100644
--- a/tzshapefilegen/main.go
+++ b/tzshapefilegen/main.go
@@ -14,6 +14,7 @@ import (
 	"os"
 
 	json "github.com/json-iterator/go"
+	"github.com/paulmach/orb/encoding/mvt"
 	"github.com/paulmach/orb/geojson"
 	"github.com/paulmach/orb/simplify"
 )
@@ -136,7 +137,12 @@ func orbExec(combinedJSON []byte) ([]byte, int, error) {
 	}
 	fc.Features = features
 	tzCount := len(fc.Features)
-	reducedJSON, err := fc.MarshalJSON()
+	data := map[string]*geojson.FeatureCollection{
+		"data": fc,
+	}
+	layers := mvt.NewLayers(data)
+	// layers.Simplify(simplify.VisvalingamThreshold(0.0001))
+	reducedJSON, err := mvt.Marshal(layers)
 	if err != nil {
 		log.Printf("Error: could not marshal reduced.json: %v\n", err)
 		return nil, 0, err