A relatively painless way (if .htaccess is too hard for your contact to implement) is to use rel canonical to point to the url you want since Google and Bing will (eventually) notice your canonical tag.
So, for http://www.cascadevillagehotel.com/index.htm you could add a tag like the one below into your index.htm file in the head section:
You should also make sure that any links to the home page refer to http://www.cascadevillagehotel.com rather than http://www.cascadevillagehotel.com/index.htm
See http://support.google.com/webmasters/bin/answer.py?hl=en&answer=139394 for more info on rel canonical
Having said that, a 301 redirect is probably the best way to solve the problem.
BTW, I'm assuming it is an Apache server and so uses .htaccess - IIS can be a bit more tricky (see http://www.seomoz.org/blog/what-every-seo-should-know-about-iis#chaining for IIS redirects)
You could use something like this in the .htaccess file (always make a backup copy of the .htaccess file before saving it in case something goes wrong - typos etc.):
BACKUP EXISTING .htaccess FIRST!!!
RewriteEngine On
RewriteBase /
may need to uncomment the next line depending on host
#Options +FollowSymlinks
add www for non www pages - you may not need these two lines
RewriteCond %{HTTP_HOST} ^cascadevillagehotel.com$ [NC]
RewriteRule ^(.*)$ http://www.cascadevillagehotel.com/$1 [L,R=301]
The following redirect is the one for index.htm assumes the default page is /
redirect 301 /index.htm http://www.cascadevillagehotel.com/