diff --git a/chainList.json b/chainList.json
index e34c54163..9ffa3542a 100644
--- a/chainList.json
+++ b/chainList.json
@@ -289,6 +289,24 @@
       "chain": "mainnet"
     }
   },
+  {
+    "name": "River",
+    "identifier": "mainnet/river",
+    "chainId": 550,
+    "rpc": [
+      "https://towns-mainnet.calderachain.xyz/http"
+    ],
+    "explorers": [
+      "https://explorer.river.build"
+    ],
+    "superchainLevel": 0,
+    "governedByOptimism": false,
+    "dataAvailabilityType": "eth-da",
+    "parent": {
+      "type": "L2",
+      "chain": "mainnet"
+    }
+  },
   {
     "name": "Shape",
     "identifier": "mainnet/shape",
diff --git a/chainList.toml b/chainList.toml
index 74292f507..ed7ea8138 100644
--- a/chainList.toml
+++ b/chainList.toml
@@ -208,6 +208,19 @@
     type = "L2"
     chain = "mainnet"
 
+[[chains]]
+  name = "River"
+  identifier = "mainnet/river"
+  chain_id = 550
+  rpc = ["https://towns-mainnet.calderachain.xyz/http"]
+  explorers = ["https://explorer.river.build"]
+  superchain_level = 0
+  governed_by_optimism = false
+  data_availability_type = "eth-da"
+  [chains.parent]
+    type = "L2"
+    chain = "mainnet"
+
 [[chains]]
   name = "Shape"
   identifier = "mainnet/shape"
diff --git a/superchain/configs/configs.json b/superchain/configs/configs.json
index f264ec3a4..78380864c 100644
--- a/superchain/configs/configs.json
+++ b/superchain/configs/configs.json
@@ -494,6 +494,74 @@
             "UnsafeBlockSigner": "0x2270d6eC8E760daA317DD978cFB98C8f144B1f3A"
           }
         },
+        {
+          "Name": "River",
+          "l2_chain_id": 550,
+          "PublicRPC": "https://towns-mainnet.calderachain.xyz/http",
+          "SequencerRPC": "https://towns-mainnet.calderachain.xyz/http",
+          "Explorer": "https://explorer.river.build",
+          "SuperchainLevel": 0,
+          "GovernedByOptimism": false,
+          "StandardChainCandidate": false,
+          "SuperchainTime": null,
+          "batch_inbox_address": "0x9BE0c82d5bA973a9e6861695626D4F9983e80C88",
+          "Superchain": "mainnet",
+          "Chain": "river",
+          "canyon_time": 0,
+          "delta_time": 0,
+          "ecotone_time": 0,
+          "block_time": 2,
+          "seq_window_size": 21600,
+          "max_sequencer_drift": 3600,
+          "DataAvailabilityType": "eth-da",
+          "optimism": {
+            "eip1559Elasticity": 6,
+            "eip1559Denominator": 250,
+            "eip1559DenominatorCanyon": 250
+          },
+          "GasPayingToken": null,
+          "genesis": {
+            "l1": {
+              "hash": "0x1bddc3be9af64c6069d9d5c51525ae75aa75cdc24b6db5a27aae6c705ada591e",
+              "number": 19905337
+            },
+            "l2": {
+              "hash": "0x5a41f6e152b724fffb68a67b72566cbe0b4a8d8a67282cccafbcdc8fc5245f38",
+              "number": 0
+            },
+            "l2_time": 1716138071,
+            "system_config": {
+              "batcherAddr": "0x52ee324F2bCD0c5363d713eb9f62D1eE47266ac1",
+              "overhead": "0x0000000000000000000000000000000000000000000000000000000000000834",
+              "scalar": "0x010000000000000000000000000000000000000000000000000a118b0000044d",
+              "gasLimit": 30000000
+            }
+          },
+          "Addresses": {
+            "AddressManager": "0xA80349b0D79bf3154ae54066410d20eb7B8697Ac",
+            "AnchorStateRegistryProxy": "0xe66a844Fe492058ebeB6898fa52AA2453784fC04",
+            "BatchSubmitter": "0x52ee324F2bCD0c5363d713eb9f62D1eE47266ac1",
+            "Challenger": "0x318Cf0B120595B1bE66a823a83362dbae7434D3d",
+            "DelayedWETHProxy": "0x5151d699f439Ef9901d63FFD9bc18847067F70c4",
+            "DisputeGameFactoryProxy": "0xBA8a9737E20F5793d21B4DE36a6B5FFddcB06D4b",
+            "Guardian": "0x2876c43B17A5750CBea5E2A3C42718374E21D5a2",
+            "L1CrossDomainMessengerProxy": "0x22B0cd077c937b9912772B38519b6d2d91541c1A",
+            "L1ERC721BridgeProxy": "0x42AABA8A896ca6C987068Ac9a9112c2e4dcA4c96",
+            "L1StandardBridgeProxy": "0x2d51D580Cae0a644a5328E665c768C2A4c0E4a03",
+            "L2OutputOracleProxy": "0x29E7177837652ca00f05fbD2e8aA867d207B2EF8",
+            "MIPS": "0x55CaAEfA6C817d167e0C8273858Ec7CEAD71037e",
+            "OptimismMintableERC20FactoryProxy": "0xB5984cCf496a8FC2d921A5a425Bd5F7a740BE89C",
+            "OptimismPortalProxy": "0x9fDEEa19836A413C04e9672d3d09f482278e863c",
+            "PreimageOracle": "0x81C6f49c79bC83F6E118DD4d8e04456BEfbA254f",
+            "Proposer": "0x1F7D2BCe97a04D2f935C62b53fE04fed373d2d17",
+            "ProxyAdmin": "0x566c7DB023111D897F16b602B2B57f0F12f7bF44",
+            "ProxyAdminOwner": "0x2876c43B17A5750CBea5E2A3C42718374E21D5a2",
+            "SuperchainConfig": "0xb6aFBB2A7299e968c9f98f8b518bD89e670a420A",
+            "SystemConfigOwner": "0x2876c43B17A5750CBea5E2A3C42718374E21D5a2",
+            "SystemConfigProxy": "0xf565303B5326C8653E78e5f73a2984f6F778C9E8",
+            "UnsafeBlockSigner": "0x1282EA0dB437d4e08e33Ca9000689Ed3b65520fb"
+          }
+        },
         {
           "Name": "Binary Mainnet",
           "l2_chain_id": 624,
diff --git a/superchain/configs/mainnet/river.toml b/superchain/configs/mainnet/river.toml
new file mode 100644
index 000000000..66cce96bb
--- /dev/null
+++ b/superchain/configs/mainnet/river.toml
@@ -0,0 +1,58 @@
+name = "River"
+chain_id = 550
+public_rpc = "https://towns-mainnet.calderachain.xyz/http"
+sequencer_rpc = "https://towns-mainnet.calderachain.xyz/http"
+explorer = "https://explorer.river.build"
+superchain_level = 0
+governed_by_optimism = false
+batch_inbox_addr = "0x9BE0c82d5bA973a9e6861695626D4F9983e80C88"
+canyon_time = 0 # Thu 1 Jan 1970 00:00:00 UTC
+delta_time = 0 # Thu 1 Jan 1970 00:00:00 UTC
+ecotone_time = 0 # Thu 1 Jan 1970 00:00:00 UTC
+block_time = 2
+seq_window_size = 21600
+max_sequencer_drift = 3600
+data_availability_type = "eth-da"
+
+[optimism]
+  eip1559_elasticity = 6
+  eip1559_denominator = 250
+  eip1559_denominator_canyon = 250
+
+[genesis]
+  l2_time = 1716138071
+  [genesis.l1]
+    hash = "0x1bddc3be9af64c6069d9d5c51525ae75aa75cdc24b6db5a27aae6c705ada591e"
+    number = 19905337
+  [genesis.l2]
+    hash = "0x5a41f6e152b724fffb68a67b72566cbe0b4a8d8a67282cccafbcdc8fc5245f38"
+    number = 0
+  [genesis.system_config]
+    batcherAddress = "0x52ee324F2bCD0c5363d713eb9f62D1eE47266ac1"
+    overhead = "0x0000000000000000000000000000000000000000000000000000000000000834"
+    scalar = "0x010000000000000000000000000000000000000000000000000a118b0000044d"
+    gasLimit = 30000000
+
+[addresses]
+  SystemConfigOwner = "0x2876c43B17A5750CBea5E2A3C42718374E21D5a2"
+  ProxyAdminOwner = "0x2876c43B17A5750CBea5E2A3C42718374E21D5a2"
+  Guardian = "0x2876c43B17A5750CBea5E2A3C42718374E21D5a2"
+  Challenger = "0x318Cf0B120595B1bE66a823a83362dbae7434D3d"
+  Proposer = "0x1F7D2BCe97a04D2f935C62b53fE04fed373d2d17"
+  UnsafeBlockSigner = "0x1282EA0dB437d4e08e33Ca9000689Ed3b65520fb"
+  BatchSubmitter = "0x52ee324F2bCD0c5363d713eb9f62D1eE47266ac1"
+  AddressManager = "0xA80349b0D79bf3154ae54066410d20eb7B8697Ac"
+  L1CrossDomainMessengerProxy = "0x22B0cd077c937b9912772B38519b6d2d91541c1A"
+  L1ERC721BridgeProxy = "0x42AABA8A896ca6C987068Ac9a9112c2e4dcA4c96"
+  L1StandardBridgeProxy = "0x2d51D580Cae0a644a5328E665c768C2A4c0E4a03"
+  L2OutputOracleProxy = "0x29E7177837652ca00f05fbD2e8aA867d207B2EF8"
+  OptimismMintableERC20FactoryProxy = "0xB5984cCf496a8FC2d921A5a425Bd5F7a740BE89C"
+  OptimismPortalProxy = "0x9fDEEa19836A413C04e9672d3d09f482278e863c"
+  SystemConfigProxy = "0xf565303B5326C8653E78e5f73a2984f6F778C9E8"
+  ProxyAdmin = "0x566c7DB023111D897F16b602B2B57f0F12f7bF44"
+  SuperchainConfig = "0xb6aFBB2A7299e968c9f98f8b518bD89e670a420A"
+  AnchorStateRegistryProxy = "0xe66a844Fe492058ebeB6898fa52AA2453784fC04"
+  DelayedWETHProxy = "0x5151d699f439Ef9901d63FFD9bc18847067F70c4"
+  DisputeGameFactoryProxy = "0xBA8a9737E20F5793d21B4DE36a6B5FFddcB06D4b"
+  MIPS = "0x55CaAEfA6C817d167e0C8273858Ec7CEAD71037e"
+  PreimageOracle = "0x81C6f49c79bC83F6E118DD4d8e04456BEfbA254f"
diff --git a/superchain/extra/addresses/addresses.json b/superchain/extra/addresses/addresses.json
index 58beb7e90..e0ab21ba0 100644
--- a/superchain/extra/addresses/addresses.json
+++ b/superchain/extra/addresses/addresses.json
@@ -601,6 +601,30 @@
     "SystemConfigProxy": "0x525a2744134805516a45B8abb6Aa0aA1dA3809F6",
     "UnsafeBlockSigner": "0x92Dc533201e8634f0337D66a11820a8C4E902474"
   },
+  "550": {
+    "AddressManager": "0xA80349b0D79bf3154ae54066410d20eb7B8697Ac",
+    "AnchorStateRegistryProxy": "0xe66a844Fe492058ebeB6898fa52AA2453784fC04",
+    "BatchSubmitter": "0x52ee324F2bCD0c5363d713eb9f62D1eE47266ac1",
+    "Challenger": "0x318Cf0B120595B1bE66a823a83362dbae7434D3d",
+    "DelayedWETHProxy": "0x5151d699f439Ef9901d63FFD9bc18847067F70c4",
+    "DisputeGameFactoryProxy": "0xBA8a9737E20F5793d21B4DE36a6B5FFddcB06D4b",
+    "Guardian": "0x2876c43B17A5750CBea5E2A3C42718374E21D5a2",
+    "L1CrossDomainMessengerProxy": "0x22B0cd077c937b9912772B38519b6d2d91541c1A",
+    "L1ERC721BridgeProxy": "0x42AABA8A896ca6C987068Ac9a9112c2e4dcA4c96",
+    "L1StandardBridgeProxy": "0x2d51D580Cae0a644a5328E665c768C2A4c0E4a03",
+    "L2OutputOracleProxy": "0x29E7177837652ca00f05fbD2e8aA867d207B2EF8",
+    "MIPS": "0x55CaAEfA6C817d167e0C8273858Ec7CEAD71037e",
+    "OptimismMintableERC20FactoryProxy": "0xB5984cCf496a8FC2d921A5a425Bd5F7a740BE89C",
+    "OptimismPortalProxy": "0x9fDEEa19836A413C04e9672d3d09f482278e863c",
+    "PreimageOracle": "0x81C6f49c79bC83F6E118DD4d8e04456BEfbA254f",
+    "Proposer": "0x1F7D2BCe97a04D2f935C62b53fE04fed373d2d17",
+    "ProxyAdmin": "0x566c7DB023111D897F16b602B2B57f0F12f7bF44",
+    "ProxyAdminOwner": "0x2876c43B17A5750CBea5E2A3C42718374E21D5a2",
+    "SuperchainConfig": "0xb6aFBB2A7299e968c9f98f8b518bD89e670a420A",
+    "SystemConfigOwner": "0x2876c43B17A5750CBea5E2A3C42718374E21D5a2",
+    "SystemConfigProxy": "0xf565303B5326C8653E78e5f73a2984f6F778C9E8",
+    "UnsafeBlockSigner": "0x1282EA0dB437d4e08e33Ca9000689Ed3b65520fb"
+  },
   "57073": {
     "AddressManager": "0x9b7C9BbD6d540A8A4dEDd935819fC4408Ba71153",
     "AnchorStateRegistryProxy": "0xde744491BcF6b2DD2F32146364Ea1487D75E2509",
diff --git a/superchain/extra/bytecodes/0x096ce66d049d8126c8643d06c8cbe9c29f2087238281f2798bde6a0c9632e84e.bin.gz b/superchain/extra/bytecodes/0x096ce66d049d8126c8643d06c8cbe9c29f2087238281f2798bde6a0c9632e84e.bin.gz
new file mode 100755
index 000000000..b32830f83
Binary files /dev/null and b/superchain/extra/bytecodes/0x096ce66d049d8126c8643d06c8cbe9c29f2087238281f2798bde6a0c9632e84e.bin.gz differ
diff --git a/superchain/extra/bytecodes/0x1760322262cf5e5f88195b748471cfad1497c065348db0f6bdceb145bae0e665.bin.gz b/superchain/extra/bytecodes/0x1760322262cf5e5f88195b748471cfad1497c065348db0f6bdceb145bae0e665.bin.gz
new file mode 100755
index 000000000..22c5f7d9b
Binary files /dev/null and b/superchain/extra/bytecodes/0x1760322262cf5e5f88195b748471cfad1497c065348db0f6bdceb145bae0e665.bin.gz differ
diff --git a/superchain/extra/bytecodes/0x61ba1dda4536ffa17924e9c46cb93e3e280f2d3013d255634b38689cde8c64aa.bin.gz b/superchain/extra/bytecodes/0x61ba1dda4536ffa17924e9c46cb93e3e280f2d3013d255634b38689cde8c64aa.bin.gz
new file mode 100755
index 000000000..1dcd610ae
Binary files /dev/null and b/superchain/extra/bytecodes/0x61ba1dda4536ffa17924e9c46cb93e3e280f2d3013d255634b38689cde8c64aa.bin.gz differ
diff --git a/superchain/extra/bytecodes/0xcfa8dbc5ad45218b8d56e0d3c970edbbe2fa535da1eaad3a9910cec2cac77b4e.bin.gz b/superchain/extra/bytecodes/0xcfa8dbc5ad45218b8d56e0d3c970edbbe2fa535da1eaad3a9910cec2cac77b4e.bin.gz
new file mode 100755
index 000000000..8bf281a5c
Binary files /dev/null and b/superchain/extra/bytecodes/0xcfa8dbc5ad45218b8d56e0d3c970edbbe2fa535da1eaad3a9910cec2cac77b4e.bin.gz differ
diff --git a/superchain/extra/genesis/mainnet/river.json.gz b/superchain/extra/genesis/mainnet/river.json.gz
new file mode 100755
index 000000000..5cea74c34
Binary files /dev/null and b/superchain/extra/genesis/mainnet/river.json.gz differ
diff --git a/validation/genesis/validation-inputs/550/deploy-config.json b/validation/genesis/validation-inputs/550/deploy-config.json
new file mode 100755
index 000000000..c8bbbedb9
--- /dev/null
+++ b/validation/genesis/validation-inputs/550/deploy-config.json
@@ -0,0 +1,66 @@
+{
+  "superchainConfigGuardian": "0x2876c43B17A5750CBea5E2A3C42718374E21D5a2",
+  "finalSystemOwner": "0x2876c43B17A5750CBea5E2A3C42718374E21D5a2",
+  "l1StartingBlockTag": "0x1bddc3be9af64c6069d9d5c51525ae75aa75cdc24b6db5a27aae6c705ada591e",
+  "l1ChainID": 1,
+  "l1BlockTime": 12,
+  "l2ChainID": 550,
+  "l2BlockTime": 2,
+  "maxSequencerDrift": 3600,
+  "sequencerWindowSize": 21600,
+  "channelTimeout": 300,
+  "p2pSequencerAddress": "0x1282EA0dB437d4e08e33Ca9000689Ed3b65520fb",
+  "batchInboxAddress": "0x9be0c82d5ba973a9e6861695626d4f9983e80c88",
+  "batchSenderAddress": "0x52ee324F2bCD0c5363d713eb9f62D1eE47266ac1",
+  "l2OutputOracleSubmissionInterval": 3600,
+  "l2OutputOracleStartingTimestamp": 1716138071,
+  "l2OutputOracleStartingBlockNumber": 0,
+  "l2OutputOracleProposer": "0x1F7D2BCe97a04D2f935C62b53fE04fed373d2d17",
+  "l2OutputOracleChallenger": "0x318Cf0B120595B1bE66a823a83362dbae7434D3d",
+  "finalizationPeriodSeconds": 604800,
+  "proxyAdminOwner": "0x318Cf0B120595B1bE66a823a83362dbae7434D3d",
+  "baseFeeVaultRecipient": "0x2876c43B17A5750CBea5E2A3C42718374E21D5a2",
+  "l1FeeVaultRecipient": "0x2876c43B17A5750CBea5E2A3C42718374E21D5a2",
+  "sequencerFeeVaultRecipient": "0x2876c43B17A5750CBea5E2A3C42718374E21D5a2",
+  "baseFeeVaultMinimumWithdrawalAmount": "0xde0b6b3a7640000",
+  "l1FeeVaultMinimumWithdrawalAmount": "0xde0b6b3a7640000",
+  "sequencerFeeVaultMinimumWithdrawalAmount": "0xde0b6b3a7640000",
+  "baseFeeVaultWithdrawalNetwork": 0,
+  "l1FeeVaultWithdrawalNetwork": 0,
+  "sequencerFeeVaultWithdrawalNetwork": 0,
+  "gasPriceOracleBaseFeeScalar": 1101,
+  "gasPriceOracleBlobBaseFeeScalar": 659851,
+  "gasPriceOracleOverhead": 2100,
+  "gasPriceOracleScalar": 0,
+  "enableGovernance": false,
+  "governanceTokenName": "Optimism",
+  "governanceTokenSymbol": "OP",
+  "governanceTokenOwner": "0x318Cf0B120595B1bE66a823a83362dbae7434D3d",
+  "l2GenesisBlockGasLimit": "0x1c9c380",
+  "l2GenesisBlockBaseFeePerGas": "0x3b9aca00",
+  "eip1559Denominator": 250,
+  "eip1559DenominatorCanyon": 250,
+  "eip1559Elasticity": 6,
+  "l2GenesisRegolithTimeOffset": "0x0",
+  "l2GenesisCanyonTimeOffset": "0x0",
+  "l2GenesisDeltaTimeOffset": "0x0",
+  "l2GenesisEcotoneTimeOffset": "0x0",
+  "systemConfigStartBlock": 0,
+  "requiredProtocolVersion": "0x0000000000000000000000000000000000000000000000000000000000000000",
+  "recommendedProtocolVersion": "0x0000000000000000000000000000000000000000000000000000000000000000",
+  "fundDevAccounts": false,
+  "faultGameAbsolutePrestate": "0x035ac9f319e41b6dc184bf1153c9dbaead5d1e89c5ecc4212808ff5cc8f33b08",
+  "faultGameMaxDepth": 73,
+  "faultGameClockExtension": 120,
+  "faultGameMaxClockDuration": 1200,
+  "faultGameGenesisBlock": 0,
+  "faultGameGenesisOutputRoot": "0x0000000000000000000000000000000000000000000000000000000000000000",
+  "faultGameSplitDepth": 32,
+  "faultGameWithdrawalDelay": 1200,
+  "preimageOracleMinProposalSize": 1800000,
+  "preimageOracleChallengePeriod": 120,
+  "proofMaturityDelaySeconds": 12,
+  "disputeGameFinalityDelaySeconds": 6,
+  "respectedGameType": 0,
+  "useFaultProofs": false
+}
\ No newline at end of file
diff --git a/validation/genesis/validation-inputs/550/meta.toml b/validation/genesis/validation-inputs/550/meta.toml
new file mode 100755
index 000000000..a3b748964
--- /dev/null
+++ b/validation/genesis/validation-inputs/550/meta.toml
@@ -0,0 +1,4 @@
+genesis_creation_commit = "e6ef3a900c42c8722e72c2e2314027f85d12ced5"
+node_version = "18.12.1"
+monorepo_build_command = "pnpm"
+genesis_creation_command = "forge1"