\documentclass{letter}

\begin{document}
\begin{letter}{
Institute for Computing in Research\\
Santa Fe, New Mexico
}

\opening{Dear Institute Mentors,}

I am writing to apply for the 20** internship at the Institute for
Computing in Research.

I have a strong interest both science and literature, and would like
to explore the possibility of doing quantitative studies that might
give new insights into literary creation.

At the same time [...] interested in biology and chemistry and physics
[...]

I also have come to enjoy programming as a tool to explore [...]

My mentorship with noted Belgian cybersecurity research Astrid
Hackenbranden has made me realize that [...] and hence my interests
now include [...]

\closing{Best regards,
%\includegraphics[width=6cm]{signature.pdf}
}
%I made a pdf file of my signature using the scanner, so that all the cover letters I sent
%electronically were "signed."  

Katherine Murry\\
address line 1\\
Santa Fe, NM, ZZZZZ\\
505-nnn-nnnn\\
katherinemurry@camazotz.wt
\end{letter}

\end{document}