diff --git a/README.md b/README.md
index e5d98b6c..5ce2b303 100644
--- a/README.md
+++ b/README.md
@@ -205,6 +205,16 @@ To improve the speed of syncing with the Zcash network, the SDK contains a serie
 
 To update the checkpoints, see [Checkmate](https://github.com/zcash-hackworks/checkmate).
 
+We generally recommend adding new checkpoints every few weeks.  By convention, checkpoints are added in block increments of 10,000 which provides a reasonable tradeoff in terms of number of checkpoints versus performance.
+
+There are two special checkpoints, one for sapling activation and another for orchard activation.  These are mentioned because they don't follow the "round 10,000" rule.
+ * Sapling activation
+     * Mainnet: 419200
+     * Testnet: 280000
+ * Orchard activation
+     * Mainnet: 1687104
+     * Testnet: 1842420
+
 ## Publishing
 
 Publishing instructions for maintainers of this repository can be found in [PUBLISHING.md](PUBLISHING.md)
diff --git a/sdk-lib/src/main/assets/co.electriccoin.zcash/checkpoint/mainnet/1687104.json b/sdk-lib/src/main/assets/co.electriccoin.zcash/checkpoint/mainnet/1687104.json
new file mode 100644
index 00000000..54cea28e
--- /dev/null
+++ b/sdk-lib/src/main/assets/co.electriccoin.zcash/checkpoint/mainnet/1687104.json
@@ -0,0 +1,8 @@
+{
+  "network": "main",
+  "height": "1687104",
+  "hash": "0000000000d723156d9b65ffcf4984da7a19675ed7e2f06d9e5d5188af087bf8",
+  "time": 1654019405,
+  "saplingTree": "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",
+  "orchardTree": "000000"
+}
diff --git a/sdk-lib/src/main/assets/co.electriccoin.zcash/checkpoint/testnet/1842420.json b/sdk-lib/src/main/assets/co.electriccoin.zcash/checkpoint/testnet/1842420.json
new file mode 100644
index 00000000..4f5396a4
--- /dev/null
+++ b/sdk-lib/src/main/assets/co.electriccoin.zcash/checkpoint/testnet/1842420.json
@@ -0,0 +1,8 @@
+{
+  "network": "test",
+  "height": "1842420",
+  "hash": "0006d75c60b3093d1b671ff7da11c99ea535df9927c02e6ed9eb898605eb7381",
+  "time": 1650360552,
+  "saplingTree": "011943e7b8f4187ac97b1968b0c7ebde20d4c0d6be3cb86885e1a812c66da4512d001001099286d1d7ad904b1c398f4950c8d78377e19b47ae0ebecbc8788446547bb5530000015020d0a93940caf0c9208e97b7525d241b13e64fcd1ca3fc6f2009bdcf732502000000017bbe520c0277c9670a339e80f676ba8393f338c7adbcb1a20a03ded90c9efd4000000000000117ddeb3a5f8d2f6b2d0a07f28f01ab25e03a05a9319275bb86d72fcaef6fc01501f08f39275112dd8905b854170b7f247cf2df18454d4fa94e6e4f9320cca05f24011f8322ef806eb2430dc4a7a41c1b344bea5be946efc7b4349c1c9edb14ff9d39",
+  "orchardTree": "000000"
+}