DStretch Presentations                   DStretch Home
My presentations started out by promoting DStretch at archaeology conferences.  Later I have used them to document especially important or interesting sites.  I even have a presentation about a mule trip I did to search for special cottonwood trees hidden in a remote canyon in the Sierra de Guadalupe.  I am especially proud of the presentations I gave about Cueva San Borjitas and the migrations of the Great Mural artists.

El Valle TMule
                Trip
El Valle Mule Trip
A mule trip to a remote valley in Baja California Sur (PDF.)  I gave this talk at RA2023.  Ken Hedges has edited the talk to fix some problems with the video (That I caused.)  Here is the video.
ARARA 2023
Little Great Murals
More about the small figures found at many great mural locations.  In addition to those at  Cerro Murciélago which I presented at Rock Art 2022,  I look at the rock art at Cueva Flechas, Monos de San Juan and at sites I visited on mule trips led by Eve Ewing.  It seems to me that the shamanism explanation of this art has a problem if these paintings were a family affair.  I gave this talk at ARARA2023 in Tuscon.
RA 2022
                Presentation
Rock Art Near Cerro Murciélago, Baja California Sur
Near Cerro Murciélago are a number of Great Mural pictograph sites.    I have talked about some of the sites before (see Patterns of Figure Placement below.) This talk at Rock Art 2022 emphasizes the small figures in the panels.  I believe they were done by children and that the paintings record a visit by a family. The talk I gave was recorded and can be seen here.
Toños Talk
A Leviathan in the Desert (Toños)
Toños  is a Great Mural site containing an incredible life size painting of an orca (killer whale).  This is the largest pictograph in the world!  There is much general information in the talk about orcas and the art and rock art  inspired by them done by native peoples in North America. I gave this talk at ARARA 2019 in Flagstaff and Rock Art 2019 in San Diego.  It was published in American Indian Rock Art 46:97-106 (PDF).
 

Codornices Presentation
Rancho Codornices: Great Mural Painted Sites in Baja California north of the known boundaries of Great Mural Art
Rancho Codornices has Great Mural pictographs of striking beauty in addition to Northern Abstract sites.  I have given this talk at XIII Conferencia Internacional ANTROPOLOGÍA ´2016 in La Habana, Cuba,  Rock Art 2016 , SCA 2017, and ARARA 2017.
Ugarte's Güéribo
                Grove
In Search of Padre Ugarte's Güéribo Grove
I gave this talk at the Yerba Buena chapter California Native Plants meeting in San Francisco May 11, 2016.  It documents a mule trip I did in March 2015 searching for the grove that Padre Ugarte logged for timber to build the ship El Triunfo de la Cruz in 1719.
Great
                Mural Migration Presentation
Migrations of the Great Mural Artists
An important use of rock art to document the migration of peoples.  A paper based on the presentations has appeared in Rock Art Papers v18, edited by Ken Hedges and published in 2016 by the San Diego Rock Art Association.  Here is a PDF (9mb).  I have given a variant of this presentation at several conferences in 2014 and 2015: Balances (in La Paz for the first time), Rock Art (San Diego), MORAW (Zzyzx), SCA (Redding), SAA (San Francisco), and IFRAO (Cáceres, Spain). 
ARARA 2014
                Presentation
Two Great Mural Sites in the Sierra de San Borja:The Guadalupe Connection
 I describe two sites from the Sierra de San Borja and show a connection between the art there and the Sierra de Guadalupe.  This may indicate the place of origin of the San Borja painters.  Presented at the ARARA 2014 conference in Rock Springs, WY.
Rock Art, Balances 2013
A Tale of two Cañadas
Describes a new Great Mural site in the Sierra de San Borja.  It is not really the northernmost Great Mural site.  I had forgotten about Cordornices. Presented at Rock Art 2013 in San Diego, November 2, 2013, INAH Balances Conference in Guadalupe Valley, November 22, 2013, and a shorter version at SCA 2014 in Visalia, March 22 2014. SCA Proceedings:Harman, Jon, 2014, "A Tale of Two Cañadas: The Most Northerly Great Mural Site Yet Discovered," 28:206-218.
Patterns of Figure
                Placement in Great Mural Art near Mission Santa
                Gertrudis
Patterns of Figure Placement in Great Mural Art near Mission Santa Gertrudis
Presented at the INAH Balances Conference in Mexico City, September 24, 2012, at Rock Art 2012 in San Diego, November 3, 2012 and IFRAO in Albuquerque May 28, 2013.
SCA 2012 Presentation
Three Pictograph Sites near Mission San Borja, Baja California
Documentation of Northern Abstract sites near Mission San Borja.  See also A Tale of two Cañadas.  Presented at the Society for California Archaeology in San Diego, CA, March 2012
SAA/ARARA 2011
                presentation
The Monos of Cueva San Borjitas
Documentation and analysis of the monos at San Borjitas.  Presented at SAA 2011 in Sacramento, CA, and the  ARARA 2011 conference in Idaho Falls, ID.   For more about San Borjitas see Rock Art 2010 Balances 2010 and San Borjitas slideshows and visual index to images.
Rock Art
                      2010/Balances 2010
Cueva San Borjitas:Birthplace of the Great Mural Tradition
The implications of the superimpositions of monos at San Borjitas for Great Mural evolution.  Presented at Rock Art 2010 in San Diego, CA, and the Balances y Perspectivas XI conference in Ensenada, Baja California, November 2010.
Balances
                2009 Rock Art 2009
The Rock Art of Campo Monte, Baja California
Presented at Rock Art 2009 in San Diego, CA, and the Balances y Perspectivas conference in Mexicali, Baja California, November 2009.  I originally called a site La Palmira, but now I think it should be La Palmita and have made the change here.
ARARA 2008 Presentation
Using DStretch to Reveal Patterns of Figure Placement at Two Great Mural sites
Demonstrates that figure placement at these sites is not random, but follows patterns that can be recognized.  Presented at the American Rock Art Research Association meeting in Farmington, New Mexico, May 2008.
Balances 2007 Presentation
Two Great Mural Sites near Mission Santa Gertrudis, Baja California
Documentation of Santa Gertrudis Norte and Cueva Muerto.  Presented at Balances y Perspectivas conference in Mexicali, Baja California, November 2007.
Presentation at SMA 2007
Pictograph Enhancement Using DStretch
Presented at the Sociedad Mexicana de Antropología, Mexico City, Mexico, August 2007
Link
                to ARARA 2007 Presentation
Kachina Rockshelter, Nevada
Presented at the American Rock Art Research Association meeting in Billings, Montana, July 2007.
Link to NAA 2007 presentation
Alvin's Last Road Trip: Pictograph Sites in the Snake Range
Presented at the Nevada Archaeological Association session in honor of Alvin McLane Ely, NV, April 2007.
A
                Pictograph Rock Shelter in Guadalupe Canyon, Baja
                California A Pictograph Rock Shelter in Guadalupe Canyon, Baja California
Presented at Society of California Archaeology meeting San Jose, CA, March 2007.   Coauthor INAH archaeologist Antonio Porcayo.
SCA Written
                Paper
A Pictograph Rock Shelter in Guadalupe Canyon, Baja California.  Publication Version
Publication version of paper for SCA 2007 (PDF).
Rock
                Art 2006 Rocky Hill
A New Look at Rocky Hill
Wonders revealed by DStretch at this Yokuts site.  Presented at Museum of Man Rock Art conference in San Diego, CA, November 2006.
Balances 2006 Presentation
Digital Enhancement of Pictographs From Baja California
Presented at Balances y Perspectivas conference in Mexico City, Mexico, August 2006.
Balances 2005
Decorrelation Stretch Enhancement of Great Mural Paintings of Baja California
Presented at Balances y Perspectivas conference in Tijuana, Baja California, November 2005.
Rock Art 2005 Conference
Pictograph Image Enhancement using Decorrelation Stretch
Presented at Museum of Man Rock Art conference in San Diego, CA, November 2005.
Link To Algorithm Description
Using Decorreation Stretch to Enhance Rock Art Images
One of the first DStretch presentations.  Poster presented at American Rock Art Research Association meeting in Reno, NV, May 2005.