FileInfo.com


.LYR File Extension


File Type ArcView Layer File
File Format File
Common? No
File Description Contains information available in ArcView's layer properties dialog box; may include symbols, display settings, joined table details, definition queries, labeling properties, and annotation display properties.

LYR files are similar to Legend (.AVL) files, but may contain much more information and are saved in a binary format rather than as a text file.
Program(s) that open lyr files Windows: ESRI ArcView

Information from FileInfo.com - The File Extensions Resource.
http://www.fileinfo.com/extension/lyr