The Indian Lands download file is approximately 20 MB in size, so do not try to download it using a slow modem connection.
Some people have trouble downloading a Zipped file from an http site.
If you experience difficulty, go to this site. The Congressional Districts coverage originally came from the U.S. Census Bureau. This directory contains maps that are suitable for printing on large format plotters. There are several versions of each map. Download the one that best fits your needs.