diff --git a/CHANGELOG-bridgetree.md b/CHANGELOG-bridgetree.md
new file mode 100644
index 0000000..e30cf7f
--- /dev/null
+++ b/CHANGELOG-bridgetree.md
@@ -0,0 +1,102 @@
+# Changelog
+All notable changes to this project will be documented in this file.
+
+The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
+and this project adheres to Rust's notion of
+[Semantic Versioning](https://semver.org/spec/v2.0.0.html).
+
+## [Unreleased]
+
+## [bridgetree-v0.2.0] - 2022-05-10
+
+The `bridgetree` crate is a fork of `incrementalmerkletree`, with the contents
+of the `bridgetree` module moved to the crate root. As such, a number of things
+have been significantly refactored and/or reorganized. In the following
+documentation, types and operations that have been removed are referred to by
+their original paths; types that have been moved to the root module are
+referred to by their new location.
+
+### Changed relative to `incrementalmerkletree-v0.3.0`
+
+- The `MerkleBridge` type has been substantially refactored to avoid storing duplicate
+  ommer values.
+
+- `Position::is_complete` has been renamed to `Position::is_complete_subtree`.
+- The return type of `NonEmptyFrontier::leaf` has changed.
+- The arguments to `NonEmptyFrontier::new` have changed.
+- `NonEmptyFrontier::root` now takes an optional `root_level` argument.
+- `NonEmptyFrontier::leaf` now always returns the leaf hash.
+- `NonEmptyFrontier::ommers`' return values now include the sibling of the leaf,
+  if the frontier's leaf position is odd. That is, the leaf is now always a leaf,
+  instead of a potentially-half-full subtree.
+- The arguments to `Frontier::from_parts` have changed.
+- The `Ord` bound on the `H` type parameter to `MerkleBridge<H>` has been removed.
+- `Altitude` has been renamed to `Level`
+- `witness` is now used as the name of the operation to construct the witness for a leaf.
+  We now use `mark` to refer to the process of marking a node for which we may later wish
+  to construct a witness.
+  - `BridgeTree::witness` has been renamed to `BridgeTree::mark`
+  - `BridgeTree::witnessed_positions` has been renamed to `BridgeTree::marked_positions`
+  - `BridgeTree::get_witnessed_leaf` has been renamed to `BridgeTree::get_marked_leaf`
+  - `BridgeTree::remove_witness` has been renamed to `BridgeTree::remove_mark`
+  - `BridgeTree::authentication_path` has been renamed to `BridgeTree::witness`
+  - `BridgeTree::witnessed` has been renamed to `BridgeTree::marked`
+  - `BridgeTree::witnessed_indices` has been renamed to `BridgeTree::marked_indices`
+
+The following types have been moved from the `bridgetree` module of
+`incrementalmerkletree` to the crate root:
+
+- `NonEmptyFrontier`
+- `Frontier`
+- `MerkleBridge`
+- `BridgeTree`
+
+### Added relative to `incrementalmerkletree-v0.3.0`
+
+- `NonEmptyFrontier::value_at`
+- `NonEmptyFrontier::authentication_path`
+- `ContinuityError` and `WitnessingError` error types for reporting errors in
+  constructing witnesses.
+- `MerkleBridge::position_range`
+- `MerkleBridge::tracking`
+- `MerkleBridge::ommers`
+- `MerkleBridge::current_leaf`
+- `Position::is_odd`
+- `Position::ommer_index`
+- `Position::root_level`
+- `Position::past_ommer_count`
+- `Address` A type used to uniquely identify node locations within a binary tree.
+
+A `test-dependencies` feature has been added. This makes available a `testing`
+module to users of this crate, which contains `proptest` generators for types
+from this crate as well as a number of tools for comparison testing between
+`Tree` implementations.  The `Frontier` and `Tree` traits have been moved to
+the `testing` module, as there is not another good use case for polymorphism
+over tree implementations; the API of `Tree` is excessively specialized to the
+`BridgeTree` use patterns case.
+
+The `Tree` interface reflects the renaming of `witness` to `mark` described above:
+  - `Tree::witness` has been renamed to `Tree::mark`
+  - `Tree::witnessed_positions` has been renamed to `Tree::marked_positions`
+  - `Tree::get_witnessed_leaf` has been renamed to `Tree::get_marked_leaf`
+  - `Tree::remove_witness` has been renamed to `Tree::remove_mark`
+  - `Tree::authentication_path` has been renamed to `Tree::witness`
+
+### Removed relative to `incrementalmerkletree-0.3.0`
+
+- `bridgetree::Leaf` 
+- `bridgetree::AuthFragment`
+- `NonEmptyFrontier::size`
+- `NonEmptyFrontier::max_altitude`
+- `NonEmptyFrontier::current_leaf`
+- `NonEmptyFrontier::witness`
+- `MerkleBridge::root`
+- `MerkleBridge::root_at_altitude`
+- `MerkleBridge::auth_fragments`
+- `BridgeTree::check_consistency`
+- `Position::altitudes_required`
+- `Position::all_altitudes_required`
+- `Position::auth_path`
+- `Position::max_altitude`
+- `Position::ommer_altitudes`
+- `impl Sub<u8> for Altitude`
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 0801c80..5b8a0d9 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,10 @@ and this project adheres to Rust's notion of
 
 ## [Unreleased]
 
+### Removed
+
+- The `bridgetree` module has been moved out a to a separate `bridgetree` crate.
+
 ## [0.3.0] - 2022-05-10
 
 ### Added
diff --git a/Cargo.toml b/Cargo.toml
index 11ca152..ce8070c 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "bridgetree"
-version = "0.1.0"
+version = "0.2.0"
 authors = [
     "Kris Nuttycombe <kris@nutty.land>",
     "Sean Bowe <ewillbefull@gmail.com>",