From 5b180d9ce1d382a5b34b2eb3a99bfcef871f075a Mon Sep 17 00:00:00 2001
From: JT <45159255+TameTheGame@users.noreply.github.com>
Date: Sun, 11 Oct 2026 19:12:33 -0400
Subject: [PATCH] docs(UcnFile): mention MODFLOW 6 GWT concentration file
 support

UcnFile has read MODFLOW 6 GWT concentration files since #2718, but the
module summary and class notes still describe it as an MT3DMS reader.
Name both file types, note that the header layout is detected from the
file, and add a short GWT example.

Refs #2784
---
 flopy/utils/binaryfile/__init__.py | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/flopy/utils/binaryfile/__init__.py b/flopy/utils/binaryfile/__init__.py
index fc349eeb5..18ac5bc2d 100644
--- a/flopy/utils/binaryfile/__init__.py
+++ b/flopy/utils/binaryfile/__init__.py
@@ -4,7 +4,7 @@
 
 *  HeadFile (Binary head file.  Can also be used for drawdown)
 *  HeadUFile (Binary MODFLOW-USG unstructured head file)
-*  UcnFile (Binary concentration file from MT3DMS)
+*  UcnFile (Binary concentration file from MT3DMS or MODFLOW 6 GWT)
 *  CellBudgetFile (Binary cell-by-cell flow file)
 
 """
@@ -1321,8 +1321,9 @@ class UcnFile(BinaryLayerFile):
     Notes
     -----
     The UcnFile class provides simple ways to retrieve 2d and 3d
-    concentration arrays from a MT3D binary head file and time series
-    arrays for one or more cells.
+    concentration arrays from an MT3D or MODFLOW 6 GWT binary
+    concentration file and time series arrays for one or more cells.
+    The file type is detected from the first record header.
 
     The BinaryLayerFile class is built on a record array consisting of
     headers, which are record arrays of the modflow header information
@@ -1338,6 +1339,9 @@ class UcnFile(BinaryLayerFile):
     >>> ucnobj.headers
     >>> rec = ucnobj.get_data(kstpkper=(0, 0))
 
+    >>> gwtobj = bf.UcnFile('gwt.ucn')  # MODFLOW 6 GWT concentration file
+    >>> conc = gwtobj.get_alldata()
+
     """
 
     def __init__(