Reproducing an official letterhead

See the edit below.

Here's my first attempt at this. The code is reasonably commentated but essentially I'm using textpos for placing the logo, tikz for adding the extra horizontal line, and geometry to set the margins. The subheader is placed using textpos and \hfill. The footer is placed at the bottom of the page using \vfill. This works for one-page letters, but not for longer letters (which will hopefully be avoided anyways). A better solution might be to use fancyhdr.

\documentclass{article}

\usepackage[dvinames]{xcolor}
% Measurements are taken directly from the guide
\usepackage[top=2in,left=1.5in,bottom=0.5in,right=0.625in]{geometry}
\usepackage{graphicx}
\usepackage[colorlinks=false,
            pdfborder={0 0 0},
            ]{hyperref}
\usepackage{lipsum}
\usepackage[absolute]{textpos}
\usepackage{tikz}
\usetikzlibrary{calc}
% A nice serif font, but no the prescribed nonfree ITC stone
\usepackage[oldstylenums]{kpfonts}
\usepackage[T1]{fontenc}

% No paragraph indentation
\parindent0pt
\setlength{\parskip}{0.8\baselineskip}
\raggedright
\pagestyle{empty}
% Define WSU official colors
\definecolor{WSUcrimson}{RGB}{152,30,50}
\definecolor{WSUgray}{HTML}{5e6a71}
% Ensure consistency in the footer
\urlstyle{sf}

\begin{document}

Date
\bigskip

Prof.~Wisman\\
Department of Wisemen\\
Wise State University \\
Wisetown, Wise\ \ 12345-6789\\
USA

Dear Prof.~Wiseman:

% Write the body of the letter
\lipsum[1]

Sincerely,
\vspace{4\baselineskip}

Me Myselfovsky \\
Assistant Professor


% -------------------------------------------------------
% Add logo, the text under the crimson line, and the line itself
\begin{textblock*}{2in}[0.3066,0.39](1.5in,1.33in)
    \includegraphics[width=2in]{WSUlogo}
\end{textblock*}
\begin{textblock*}{6.375in}(1.5in,1.4in)   % 6.375=8.5 - 1.5 - 0.625
    \sffamily
    \hfill \color{WSUgray} School of Electrical Engineering and Computer Science\\
    \hfill Dr.~Me Myselfovsky, Assistant Professor
\end{textblock*}
\begin{tikzpicture}[remember picture,overlay]
    \draw[color=WSUcrimson,line width=1pt] (current page.north west)+(1.5in,-1.33in) -- ($(-0.625in,-1.33in)+(current page.north east)$);
\end{tikzpicture}

% Add the footnote. A better way would be to use fancyhdr
\vfill
{\footnotesize\color{WSUgray}\sffamily
PO Box 642752, Pullman, WA 99164-2752\\[-0.1\baselineskip]
(509) 335-6249 \textbullet\ Fax: (509) 335-3818 \textbullet\ \url{[email protected]} \textbullet\ \url{http://eecs.wsu.edu/~me}
}
\end{document}

Here's the result: WSU Letterhead in LaTeX


EDIT


The following is a better way to do this. The common definitions are put in a separate file. Headers and footers are used to place the letterhead components, so there is no problem with letters that are longer than one page. \AtBeginDocument and \AtEndDocument are used to place the salutation and signature. The actual letter just needs to \input these definitions and add appropriate \renewcommands.

Common Definitions:

% Define WSU official colors
\usepackage[dvinames]{xcolor}
\definecolor{WSUcrimson}{RGB}{152,30,50}
\definecolor{WSUgray}{HTML}{5e6a71}

% Measurements are taken directly from the guide
\usepackage[top=2in,left=1.5in,bottom=0.5in,right=0.625in]{geometry}
\usepackage{graphicx}
\usepackage[colorlinks=false,
            pdfborder={0 0 0},
            ]{hyperref}
\usepackage[absolute]{textpos}
\usepackage{ifthen}
\usepackage{soul}


% --- For placement of the horizontal line
\usepackage{tikz}
\usetikzlibrary{calc}

% --- A nice serif font (palatino), but not the prescribed nonfree ITC stone
\usepackage[sc,osf]{mathpazo}
\linespread{1.05}

% Remove paragraph indentation
\parindent0pt
\setlength{\parskip}{0.8\baselineskip}
\raggedright
\pagestyle{empty}
% Ensure consistency in the footer
\urlstyle{sf}

\providecommand\WSUfromname{Me Myselfovsky}
\providecommand\WSUfromtitle{Assistant Professor}
\providecommand\WSUfromdegree{Ph.D.}
\providecommand\WSUfromdept{School of Electrical Engineering and Computer Science}
\providecommand\WSUfromaddress{PO Box 642752, Pullman, WA 99164-2752}
\providecommand\WSUfromtel{(509) 335-5555}
\providecommand\WSUfromfax{(509) 335-6666}
\providecommand\WSUfromemail{\url{[email protected]}}
\providecommand\WSUfromweb{\url{http://eecs.wsu.edu/~me}}
\providecommand\WSUtoname{Dr.~Wiseman}
\providecommand\WSUtoaddress{Department of Wisemen\\
                            Wise State University \\
                            Wisetown, Wise\ \ 12345-6789\\
                            USA}
\providecommand\WSUdate{\today}
\providecommand\WSUopening{Dear \WSUtoname}
\providecommand\WSUclosing{Sincerely}
% Update this and the next line to the correct path
\providecommand\WSUsignaturefile{AleeSignatureVector}
\providecommand\WSUlogofile{WSUlogo}
\providecommand\WSUenclosure{}

\usepackage{fancyhdr}
\pagestyle{fancy}

\renewcommand{\footrulewidth}{0pt}
\fancyfoot{}
\fancyfoot[L]{%
    {\footnotesize\color{WSUgray}\sffamily
    \WSUfromaddress\\[-0.1\baselineskip]
    \WSUfromtel\ \textbullet\ Fax: \WSUfromfax\ \textbullet\ \WSUfromemail\ \textbullet\ \WSUfromweb}\color{black}}

\fancyhead{}
\fancyhead[L]{%
    \begin{textblock*}{2in}[0.3066,0.39](1.5in,1.33in)
        \includegraphics[width=2in]{\WSUlogofile}
    \end{textblock*}
    \begin{textblock*}{6.375in}(1.5in,1.4in)   % 6.375=8.5 - 1.5 - 0.625
        \sffamily
        \hfill \color{WSUgray} \WSUfromdept
        \\ \hfill \WSUfromname, \WSUfromdegree
    \end{textblock*}
    \begin{tikzpicture}[remember picture,overlay]
        \draw[color=WSUcrimson,line width=0.7pt] (current page.north west)+(1.5in,-1.33in) -- ($(-0.625in,-1.33in)+(current page.north east)$);
    \end{tikzpicture}}
\renewcommand{\headrulewidth}{0pt}


\AtBeginDocument{
    % Text lines should be less than 6in long
    \newgeometry{top=2in,left=1.5in,bottom=1.2in,right=1in}

    \WSUdate
    \bigskip

    \WSUtoname\ifthenelse{\equal{\WSUtoname}{}}{}{\\}
    \WSUtoaddress
    \bigskip

    \WSUopening\par
    }

\AtEndDocument{
    \par\vspace{2ex}
    \WSUclosing,

    \ifthenelse{\equal{\WSUsignaturefile}{}}{\bigskip\bigskip}{\includegraphics[width=1.2in]{\WSUsignaturefile}\\[-0.2\baselineskip]}

    \WSUfromname \\
    \WSUfromtitle\ifthenelse{\equal{\WSUfromtitle}{}}{}{\\}
    \WSUenclosure

Letter Body:

This can be as simple as the following:

\documentclass{article}

\usepackage{lipsum}
\input{WSUletterdefs}

\begin{document}
\lipsum[1-2]
\end{document}

First, you need to check WSU's usage guidelines to make sure you are not violating any rules, my guess is you are, with respect to the logo usage. Assuming you can legally use the logo on your desired version the letter head layout, I wouldn't use LaTeX exclusively for the layout. The problem I see is the line in the logo. A pure LaTeX solution would require adding a perfectly matched line (color, thickness, and position) to extend the existing line. I would modify extend the line in the logo to be the full page width in a vector graphics program (e.g., Inkscape or Illustrator). I would also add the text in the matched color and font to the line. I would also create a vector graphic version of the footer with matched color and font. The advantage of making the header and footers into images is that you do not need to have the corresponding font installed on all computers that will compile the letters. It also means you do not always have to use xelatex.

Once you have these two images adding them to the header (flush right to get the overhang into the left margin) and footer (flush left) at the approraite heights can be done with fancyhdr. You can then use any font in the text body.