For Colorado, here are the email contact points for Senators Michael Bennet and Mark Udall.
http://www.markudall.senate.gov/?p=contact
http://www.bennet.senate.gov/contact/

and for Congress here are the contacts for Mike Coffman, Diana Degette, and Ed Perlmutter.
http://forms.house.gov/coffman/webforms/issue_subscribe.htm
http://degette.house.gov/index.php?option=com_content&view=article&id=483&Itemid=202
https://forms.house.gov/perlmutter/webforms/contact.shtml

To contact your current Senator use this list to find the contact site. Remember, this list will change for 2013.
http://www.senate.gov/general/contact_information/senators_cfm.cfm

To contact your Representative in the House of Representatives, use this list to find any or all of the Representatives from your state, and remember this list will change for 2013.
http://www.house.gov/representatives/

Remember, we all elected these people, be sure not to let them assume why we cast our vote for them.
Tell them why!