diff --git a/Cargo.lock b/Cargo.lock
index 74835ea..8408497 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -960,6 +960,27 @@ dependencies = [
  "syn 2.0.89",
 ]
 
+[[package]]
+name = "derive_more"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4a9b99b9cbbe49445b21764dc0625032a89b145a2642e67603e1c936f5458d05"
+dependencies = [
+ "derive_more-impl",
+]
+
+[[package]]
+name = "derive_more-impl"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cb7330aeadfbe296029522e6c40f315320aba36fc43a5b3632f3795348f3bd22"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 2.0.89",
+ "unicode-xid",
+]
+
 [[package]]
 name = "diff"
 version = "0.1.13"
@@ -2018,6 +2039,7 @@ dependencies = [
  "boilerplate",
  "chrono",
  "clap",
+ "derive_more",
  "html-escaper",
  "lettre",
  "neptune-cash",
@@ -3268,7 +3290,7 @@ dependencies = [
  "arbitrary",
  "const_format",
  "hex",
- "itertools 0.12.1",
+ "itertools 0.13.0",
  "ndarray",
  "num",
  "num-traits",
diff --git a/Cargo.toml b/Cargo.toml
index 2eabf70..e9f5638 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -34,6 +34,7 @@ chrono = "0.4.34"
 # only should be used inside main.rs, for the binary.
 anyhow = "1.0.86"
 arc-swap = "1.7.1"
+derive_more = { version = "1.0.0", features = ["display"] }
 
 [patch.crates-io]
 # 694f27daf78aade0ed0dc07e3babaab036cd5572 is tip of branch: master as of 2024-04-30
diff --git a/src/main.rs b/src/main.rs
index 447164a..a5ce3f5 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -36,7 +36,8 @@ async fn main() -> Result<(), anyhow::Error> {
     // this will log warnings if smtp not configured or mis-configured.
     alert_email::check_alert_params();
 
-    tokio::task::spawn(neptune_rpc::watchdog(app_state));
+    tokio::task::spawn(neptune_rpc::watchdog(app_state.clone()));
+    tokio::task::spawn(neptune_rpc::blockchain_watchdog(app_state));
 
     info!("Running on http://localhost:{port}");
 
diff --git a/src/model/config.rs b/src/model/config.rs
index 2e01e62..87a0ac3 100644
--- a/src/model/config.rs
+++ b/src/model/config.rs
@@ -38,6 +38,10 @@ pub struct Config {
     #[clap(long, default_value = "10", value_name = "seconds")]
     pub neptune_rpc_watchdog_secs: u64,
 
+    /// Sets interval in seconds to check that block-height has increased
+    #[clap(long, default_value = "3600", value_name = "seconds")]
+    pub neptune_blockchain_watchdog_secs: u64,
+
     /// admin email for receiving alert emails
     #[arg(long, value_name = "email")]
     pub admin_email: Option<String>,
diff --git a/src/neptune_rpc.rs b/src/neptune_rpc.rs
index 0c8a06d..8724324 100644
--- a/src/neptune_rpc.rs
+++ b/src/neptune_rpc.rs
@@ -6,6 +6,7 @@ use chrono::DateTime;
 use chrono::TimeDelta;
 use chrono::Utc;
 use clap::Parser;
+use neptune_cash::models::blockchain::block::block_height::BlockHeight;
 use neptune_cash::rpc_server::RPCClient;
 use std::net::Ipv4Addr;
 use std::net::SocketAddr;
@@ -111,3 +112,111 @@ pub struct NeptuneRpcAlertEmail {
     now: DateTime<Utc>,
     duration: TimeDelta,
 }
+
+#[derive(Clone, Copy, derive_more::Display)]
+pub enum BlockchainState {
+    Normal,
+    Warn,
+}
+
+#[derive(boilerplate::Boilerplate)]
+#[boilerplate(filename = "email/neptune_blockchain_alert.txt")]
+pub struct NeptuneBlockchainAlertEmail {
+    config: Config,
+    last_height: BlockHeight,
+    height: BlockHeight,
+    last_blockchain_state: BlockchainState,
+    blockchain_state: BlockchainState,
+    app_started: DateTime<Utc>,
+    app_duration: TimeDelta,
+    since: DateTime<Utc>,
+    now: DateTime<Utc>,
+    duration: TimeDelta,
+}
+
+/// a tokio task that periodically pings neptune-core rpc server to ensure
+/// the blockchain keeps growing and has not stalled or shortened somehow.
+///
+/// If not connected, a single connection attempt is made for each timer iteration.
+///
+/// States:
+///   normal:  the present tip is higher than at the last check.
+///   warn:    the present tip is same or lower than at the last check.
+///
+/// Whenever the state changes a log message is printed and an email
+/// alert is sent to admin, if admin_email config field is set.  In this way,
+/// the site admin gets notified if a problem occurs, and upon recovery.
+pub async fn blockchain_watchdog(app_state: AppState) {
+    let mut last_height: BlockHeight = Default::default();
+    let mut last_blockchain_state = BlockchainState::Normal;
+    let app_started = chrono::offset::Utc::now();
+    let mut since = chrono::offset::Utc::now();
+    let watchdog_secs = app_state.load().config.neptune_blockchain_watchdog_secs;
+
+    debug!("neptune-core blockchain watchdog started");
+
+    loop {
+        let result = app_state
+            .load()
+            .rpc_client
+            .block_height(context::current())
+            .await;
+
+        if let Ok(height) = result {
+            // send admin alert if there is a state change.
+            let subject = match last_blockchain_state {
+                BlockchainState::Normal if height < last_height => {
+                    "alert!  ** WARNING ** blockchain height is shrinking"
+                }
+                BlockchainState::Normal if height == last_height => {
+                    "alert!  ** WARNING ** blockchain height is stalled"
+                }
+                BlockchainState::Warn if height > last_height => {
+                    "alert!  ** Recovery ** blockchain height is growing again"
+                }
+                _ => "", // no state change
+            };
+
+            if !subject.is_empty() {
+                let blockchain_state = match last_blockchain_state {
+                    BlockchainState::Normal => BlockchainState::Warn,
+                    BlockchainState::Warn => BlockchainState::Normal,
+                };
+
+                let config = Config::parse();
+                let now = chrono::offset::Utc::now();
+                let duration = now.signed_duration_since(since);
+                let app_duration = now.signed_duration_since(app_started);
+                let body = NeptuneBlockchainAlertEmail {
+                    config,
+                    last_height,
+                    height,
+                    last_blockchain_state,
+                    blockchain_state,
+                    now,
+                    app_started,
+                    app_duration,
+                    since,
+                    duration,
+                }
+                .to_string();
+
+                let msg = format!("alert: neptune-core blockchain status change: previous: {last_blockchain_state}, now: {blockchain_state}.  prev_height: {last_height}, now_height: {height}");
+                match blockchain_state {
+                    BlockchainState::Normal => info!("{msg}"),
+                    BlockchainState::Warn => warn!("{msg}"),
+                };
+
+                let _ = alert_email::send(&app_state, subject, body).await;
+
+                last_blockchain_state = blockchain_state;
+            }
+
+            // update state.
+            last_height = height;
+            since = chrono::offset::Utc::now();
+
+            tokio::time::sleep(tokio::time::Duration::from_secs(watchdog_secs)).await;
+        }
+    }
+}
diff --git a/templates/email/neptune_blockchain_alert.txt b/templates/email/neptune_blockchain_alert.txt
new file mode 100644
index 0000000..93fceef
--- /dev/null
+++ b/templates/email/neptune_blockchain_alert.txt
@@ -0,0 +1,64 @@
+%% if matches!(self.blockchain_state, BlockchainState::Normal) {
+**** ALERT: Neptune Blockchain Height Recovery ****
+%% } else {
+**** ALERT: Neptune Blockchain Height Possible Outage ****
+%% }
+
+site: {{self.config.site_name}} at {{self.config.site_domain}}:{{self.config.listen_port}}
+
+-- Details --
+
+Event: Neptune Blockchain Height Monitor Status Change.
+
+Event Time: {{self.now.to_rfc3339()}}
+
+Event Description:
+
+%% if matches!(self.blockchain_state, BlockchainState::Normal) {
+The present block height is greater than the height at last check.  Service is restored.
+%% } else if self.last_height == self.height {
+The present block height is equal to the height at last check.
+This may indicate a problem with neptune-core.
+%% } else {
+The present block height is less than the height at last check.
+This may indicate a problem with neptune-core.
+%% }
+
+New Status:
+    blockchain monitor: {{self.blockchain_state}}
+    last_height: {{self.last_height}}
+    height: {{self.height}}
+    Now: {{self.now.to_rfc3339()}}
+
+Previous Status:
+    blockchain monitor: {{self.last_blockchain_state}}
+    Since: {{self.since.to_rfc3339()}}
+    Duration: {{self.duration}}
+
+Block Explorer Uptime:
+    Started: {{self.app_started.to_rfc3339()}}
+    Duration: {{self.app_duration}} seconds
+
+Neptune-core RPC:
+    Host: {{self.config.site_domain}}   (localhost)
+    Port: {{self.config.neptune_rpc_port}}
+
+Recommended action:
+
+%% if matches!(self.blockchain_state, BlockchainState::Normal) {
+    Check neptune-core logs to ensure it is operating correctly.
+
+    No further corrective action should be necessary.
+%% } else {
+    If only one hour has passed since the last block:
+
+        1. It is possible/likely that a block simply has not been found yet.
+        2. Check neptune-core logs to ensure it is operating correctly.
+        3. Check other nodes to ensure they are at the same block height.
+
+    if two or more hours have passed since the last block:
+        1. Check neptune-core logs to ensure it is operating correctly.
+        2. Check other nodes to ensure they are at the same block height.
+        3. Consider restarting neptune-core
+        4. Consider filing an issue, or alerting neptune-core developers.
+%% }