diff --git a/Cargo.toml b/Cargo.toml
index 245b004f1..9d13d5403 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -20,7 +20,5 @@ codegen-units = 1
 
 [patch.crates-io]
 hdwallet = { git = "https://github.com/nuttycom/hdwallet", rev = "576683b9f2865f1118c309017ff36e01f84420c9" }
-incrementalmerkletree = { git = "https://github.com/zcash/incrementalmerkletree.git", rev = "dd57b430dee7c0b163f4035fef2280cd1935036c" }
-orchard = { git = "https://github.com/zcash/orchard.git", rev = "3ddf6c49f7484ed1295bd5351317bbfe49e14472" }
 zcash_encoding = { path = "components/zcash_encoding" }
 zcash_note_encryption = { path = "components/zcash_note_encryption" }
diff --git a/components/zcash_encoding/src/lib.rs b/components/zcash_encoding/src/lib.rs
index 58c3e5389..7db5e0987 100644
--- a/components/zcash_encoding/src/lib.rs
+++ b/components/zcash_encoding/src/lib.rs
@@ -12,6 +12,7 @@ use byteorder::{LittleEndian, ReadBytesExt, WriteBytesExt};
 use nonempty::NonEmpty;
 use std::convert::TryFrom;
 use std::io::{self, Read, Write};
+use std::iter::FromIterator;
 
 /// The maximum allowed value representable as a `[CompactSize]`
 pub const MAX_COMPACT_SIZE: u32 = 0x02000000;
@@ -104,23 +105,34 @@ pub struct Vector;
 impl Vector {
     /// Reads a vector, assuming the encoding written by [`Vector::write`], using the provided
     /// function to decode each element of the vector.
-    pub fn read<R: Read, E, F>(mut reader: R, func: F) -> io::Result<Vec<E>>
+    pub fn read<R: Read, E, F>(reader: R, func: F) -> io::Result<Vec<E>>
+    where
+        F: Fn(&mut R) -> io::Result<E>,
+    {
+        Self::read_collected(reader, func)
+    }
+
+    /// Reads a CompactSize-prefixed series of elements into a collection, assuming the encoding
+    /// written by [`Vector::write`], using the provided function to decode each element.
+    pub fn read_collected<R: Read, E, F, O: FromIterator<E>>(
+        mut reader: R,
+        func: F,
+    ) -> io::Result<O>
     where
         F: Fn(&mut R) -> io::Result<E>,
     {
         let count: usize = CompactSize::read_t(&mut reader)?;
-        Array::read(reader, count, func)
+        Array::read_collected(reader, count, func)
     }
 
-    /// Writes a slice of values by writing [`CompactSize`]-encoded integer specifying the length of
-    /// the slice to the stream, followed by the encoding of each element of the slice as performed
-    /// by the provided function.
-    pub fn write<W: Write, E, F>(mut writer: W, vec: &[E], func: F) -> io::Result<()>
+    /// Writes a slice of values by writing [`CompactSize`]-encoded integer specifying the length
+    /// of the slice to the stream, followed by the encoding of each element of the slice as
+    /// performed by the provided function.
+    pub fn write<W: Write, E, F>(writer: W, vec: &[E], func: F) -> io::Result<()>
     where
         F: Fn(&mut W, &E) -> io::Result<()>,
     {
-        CompactSize::write(&mut writer, vec.len())?;
-        vec.iter().try_for_each(|e| func(&mut writer, e))
+        Self::write_sized(writer, vec.iter(), func)
     }
 
     /// Writes a NonEmpty container of values to the stream using the same encoding as
@@ -136,6 +148,21 @@ impl Vector {
         CompactSize::write(&mut writer, vec.len())?;
         vec.iter().try_for_each(|e| func(&mut writer, e))
     }
+
+    /// Writes an iterator of values by writing [`CompactSize`]-encoded integer specifying
+    /// the length of the iterator to the stream, followed by the encoding of each element
+    /// of the iterator as performed by the provided function.
+    pub fn write_sized<W: Write, E, F, I: Iterator<Item = E> + ExactSizeIterator>(
+        mut writer: W,
+        mut items: I,
+        func: F,
+    ) -> io::Result<()>
+    where
+        F: Fn(&mut W, E) -> io::Result<()>,
+    {
+        CompactSize::write(&mut writer, items.len())?;
+        items.try_for_each(|e| func(&mut writer, e))
+    }
 }
 
 /// Namespace for functions that perform encoding of array contents.
@@ -146,9 +173,22 @@ impl Vector {
 pub struct Array;
 
 impl Array {
-    /// Reads a vector, assuming the encoding written by [`Array::write`], using the provided
-    /// function to decode each element of the vector.
-    pub fn read<R: Read, E, F>(mut reader: R, count: usize, func: F) -> io::Result<Vec<E>>
+    /// Reads `count` elements from a stream into a vector, assuming the encoding written by
+    /// [`Array::write`], using the provided function to decode each element.
+    pub fn read<R: Read, E, F>(reader: R, count: usize, func: F) -> io::Result<Vec<E>>
+    where
+        F: Fn(&mut R) -> io::Result<E>,
+    {
+        Self::read_collected(reader, count, func)
+    }
+
+    /// Reads `count` elements into a collection, assuming the encoding written by
+    /// [`Array::write`], using the provided function to decode each element.
+    pub fn read_collected<R: Read, E, F, O: FromIterator<E>>(
+        mut reader: R,
+        count: usize,
+        func: F,
+    ) -> io::Result<O>
     where
         F: Fn(&mut R) -> io::Result<E>,
     {
diff --git a/zcash_primitives/Cargo.toml b/zcash_primitives/Cargo.toml
index 1a0eada2c..62fb37ca9 100644
--- a/zcash_primitives/Cargo.toml
+++ b/zcash_primitives/Cargo.toml
@@ -31,12 +31,12 @@ fpe = "0.5"
 group = "0.11"
 hdwallet = { version = "0.3.0", optional = true }
 hex = "0.4"
-incrementalmerkletree = "0.2"
+incrementalmerkletree = "=0.3.0-beta.1"
 jubjub = "0.8"
 lazy_static = "1"
 memuse = "0.2"
 nonempty = "0.7"
-orchard = "=0.1.0-beta.1"
+orchard = "=0.1.0-beta.2"
 proptest = { version = "1.0.0", optional = true }
 rand = "0.8"
 rand_core = "0.6"
@@ -55,7 +55,7 @@ features = ["pre-zip-212"]
 criterion = "0.3"
 proptest = "1.0.0"
 rand_xorshift = "0.3"
-orchard = { version = "=0.1.0-beta.1", features = ["test-dependencies"] }
+orchard = { version = "=0.1.0-beta.2", features = ["test-dependencies"] }
 
 [target.'cfg(unix)'.dev-dependencies]
 pprof = { version = "=0.6.1", features = ["criterion", "flamegraph"] }
diff --git a/zcash_primitives/src/merkle_tree/incremental.rs b/zcash_primitives/src/merkle_tree/incremental.rs
index 94e80bebb..c6cc09d58 100644
--- a/zcash_primitives/src/merkle_tree/incremental.rs
+++ b/zcash_primitives/src/merkle_tree/incremental.rs
@@ -35,6 +35,37 @@ impl HashSer for MerkleHashOrchard {
     }
 }
 
+/// Writes a usize value encoded as a u64 in little-endian order. Since usize
+/// is platform-dependent, we consistently represent it as u64 in serialized
+/// formats.
+pub fn write_usize_leu64<W: Write>(mut writer: W, value: usize) -> io::Result<()> {
+    // Panic if we get a usize value that can't fit into a u64.
+    writer.write_u64::<LittleEndian>(value.try_into().unwrap())
+}
+
+/// Reads a usize value encoded as a u64 in little-endian order. Since usize
+/// is platform-dependent, we consistently represent it as u64 in serialized
+/// formats.
+pub fn read_leu64_usize<R: Read>(mut reader: R) -> io::Result<usize> {
+    reader.read_u64::<LittleEndian>()?.try_into().map_err(|e| {
+        io::Error::new(
+            io::ErrorKind::InvalidInput,
+            format!(
+                "usize could not be decoded from a 64-bit value on this platform: {:?}",
+                e
+            ),
+        )
+    })
+}
+
+pub fn write_position<W: Write>(mut writer: W, position: Position) -> io::Result<()> {
+    write_usize_leu64(&mut writer, position.into())
+}
+
+pub fn read_position<R: Read>(mut reader: R) -> io::Result<Position> {
+    read_leu64_usize(&mut reader).map(Position::from)
+}
+
 pub fn read_frontier_v0<H: Hashable + super::Hashable, R: Read>(
     mut reader: R,
 ) -> io::Result<Frontier<H, 32>> {
@@ -47,7 +78,7 @@ pub fn write_nonempty_frontier_v1<H: HashSer, W: Write>(
     mut writer: W,
     frontier: &NonEmptyFrontier<H>,
 ) -> io::Result<()> {
-    writer.write_u64::<LittleEndian>(<u64>::from(frontier.position()))?;
+    write_position(&mut writer, frontier.position())?;
     match frontier.leaf() {
         Leaf::Left(a) => {
             a.write(&mut writer)?;
@@ -105,36 +136,19 @@ pub fn read_frontier_v1<H: HashSer + Clone, R: Read>(reader: R) -> io::Result<Fr
     }
 }
 
-pub fn write_position<W: Write>(mut writer: W, position: Position) -> io::Result<()> {
-    writer.write_u64::<LittleEndian>(position.try_into().unwrap())
-}
-
-pub fn read_position<R: Read>(mut reader: R) -> io::Result<Position> {
-    let p = reader.read_u64::<LittleEndian>()?;
-    <usize>::try_from(p).map(Position::from).map_err(|err| {
-        io::Error::new(
-            io::ErrorKind::Unsupported,
-            format!(
-                "usize could not be decoded to a 64-bit value on this platform: {:?}",
-                err
-            ),
-        )
-    })
-}
-
 pub fn write_auth_fragment_v1<H: HashSer, W: Write>(
     mut writer: W,
     fragment: &AuthFragment<H>,
 ) -> io::Result<()> {
     write_position(&mut writer, fragment.position())?;
-    writer.write_u64::<LittleEndian>(fragment.altitudes_observed().try_into().unwrap())?;
+    write_usize_leu64(&mut writer, fragment.altitudes_observed())?;
     Vector::write(&mut writer, fragment.values(), |w, a| a.write(w))
 }
 
 #[allow(clippy::redundant_closure)]
 pub fn read_auth_fragment_v1<H: HashSer, R: Read>(mut reader: R) -> io::Result<AuthFragment<H>> {
     let position = read_position(&mut reader)?;
-    let alts_observed = reader.read_u64::<LittleEndian>()? as usize;
+    let alts_observed = read_leu64_usize(&mut reader)?;
     let values = Vector::read(&mut reader, |r| H::read(r))?;
 
     Ok(AuthFragment::from_parts(position, alts_observed, values))
@@ -144,16 +158,14 @@ pub fn write_bridge_v1<H: HashSer + Ord, W: Write>(
     mut writer: W,
     bridge: &MerkleBridge<H>,
 ) -> io::Result<()> {
-    Optional::write(
-        &mut writer,
-        bridge.prior_position().map(<u64>::from),
-        |w, n| w.write_u64::<LittleEndian>(n),
-    )?;
+    Optional::write(&mut writer, bridge.prior_position(), |w, pos| {
+        write_position(w, pos)
+    })?;
     Vector::write(
         &mut writer,
         &bridge.auth_fragments().iter().collect::<Vec<_>>(),
-        |w, (i, a)| {
-            w.write_u64::<LittleEndian>(u64::from(**i))?;
+        |mut w, (pos, a)| {
+            write_position(&mut w, **pos)?;
             write_auth_fragment_v1(w, a)
         },
     )?;