1.22 million-1.25 million years ago: Resurgent volcano collapses; Valles Caldera forms.

50,000 years ago: Volcano erupts in southwest corner creating El Cajete crater and Battleship Rock formed where Valle San Antonio water and Jemez River meet.

7,500-12,000 years ago: Paleoindian hunters and gatherers occupy Valles Caldera

5,500 B.C.-500 A.D.: Archaic people occupy Valles Caldera.

500 A.D.-1650 A.D.: Ancestral Puebloan people live in Jemez Mountains and Valles Caldera.

Late 1500s to late 1700s: Spanish people settle Jemez Mountains and graze livestock in the calderas.

1860: Land grant heir of Luis Maria Cabeza de Baca given title to Valles Caldera, called the Baca Ranch.

1881-1930s: Various people buy portions of Baca Ranch and graze livestock; Bond family grazes thousands of sheep in the valley before World War II.

1935 -early 1970s: New Mexico Timber Company obtains timber rights and logs more than half the trees in the Baca Ranch.

1963: The Dunigans of Texas buy the Baca Ranch and run cattle on it

2000: Dunigans sell the land to the federal government for $101 million to create the Valles Caldera National Preserve.

April 2001: First time Valles Caldera Trust board tours Valles Caldera.

September 2001: 1,300 people win lottery for first public tour of preserve.

Oct. 2001: Former U.S. Sen. Pete Domenici staffer Gary Ziehe hired as Valles Caldera Trust's first executive director.

March 2004: Ziehe resigns; Former State Land Commissioner Ray Powell hired as executive director.

July 2003-June 2004: 7,500 people visit the Valles Caldera preserve.

August 2005: Trust board decides to focus on grazing program.

October 2005: Powell resigns as executive director

November 2005: U.S. General Accounting Office releases report "Valles Caldera Trust Has Made Some Progress but Needs to Do More to Meet Statutory Goals." Report notes problems in accounting, staff turnover and lack of strategic plan.

Spring 2006: Trust suspends summer grazing program due to drought.

July 2005-June 2006: 9,938 people visit the preserve.

May 2006: Public lands manager Jeffrey Cross hired as executive director; number of full time staff drops from 15 the prior year to 10.

2006: Staff inventories 455 miles of road in the preserve and installs a potable water system.

August 2006: 1,444 vehicles and 3,746 visitors drove the preserve in the first "open house"; main gate closed early due to rain and washed-out roads.

June-September 2008: Trust contracts with Gary Morton who pays to graze 1,998 head of cattle in the preserve.

June 2008: Cross resigns.

January 2009: Agri-businessman Gary Bratcher hired as fourth Trust executive director; two new board members appointed to Trust — Jemez Pueblo veterinarian Ray Loretto and Abiquiú rancher Virgil Trujillo.

WHAT'S AHEAD

2015: Congress to consider Valles Caldera Trust's progress in reaching goals; can extend timeline for Trust to manage preserve or decide to turn over management to the U.S. Forest Service.