When the storable-fueled Titan II and the solid-fueled Minuteman I were deployed in 1963, the Titan I and Atlas missiles became obsolete.
They were retired from service as ICBMs in early 1965.

The final launch from Vandenberg Air Force Base (VAFB) occurred on 5 March 1965.
At that time, the disposition of the 101 total production missiles was as follows:
17 were test launched from VAFB (September 1961 – March 1965)
one was destroyed in Beale AFB Site 851-C1 silo explosion 24 May 1962
54 were deployed in silos on 20 January 1965
29 were in storage at SBAMA
(three at VAFB, one at each of five bases, one at Lowry, and 20 in storage at SBAMA elsewhere)
The 83 surplus missiles remained in inventory at Mira Loma AFS.
It did not make economic sense to refurbish them as SM-65 Atlas missiles with similar payload capacities had already been converted to satellite launchers.
About 33 were distributed to museums, parks and schools as static displays (see list below).
 The remaining 50 missiles were scrapped at Mira Loma AFS near San Bernardino, CA; the last was broken up in 1972, in accordance with the SALT-I Treaty of 1 February 1972.

By November 1965 the Air Force Logistics Command had determined that the cost of modifying the widely dispersed sites to support other ballistic missiles was prohibitive, and attempts were made to find new uses.
By Spring 1966 a number of possible uses and users had been identified.
By 6 May 1966 the Air Force wanted to retain 5 Titan sites and the General Services Administration had earmarked 1 for possible use.
The USAF removed equipment it had uses for, the rest was offered to other government agencies.
Eventually no sites were retained and all were salvaged.
The chosen method was the Service and Salvage contract, which required the contractor to remove the equipment the government wanted before proceeding with scrapping.
This accounts for the varied degree of salvage at the sites today.
Most are sealed today, with one in Colorado that is easily entered but also very unsafe.
One is open for tours.

Most of the ATHENA guidance computers were given to universities.
One is in the Smithsonian.
One remained in use at Vandenberg AFB until it guided a last Thor-Agena launch in May 1972.
It had guided over 400 missiles.

On 6 September 1985 Strategic Defense Initiative (AKA "Star Wars" program), a scrapped Titan I Second Stage was used in a Missile Defense test.
The MIRACL Near Infrared Laser, at White Sands Missile Range, NM was fired at a stationary Titan I second stage that was fixed to the ground.
The second stage burst and was destroyed by the laser blast.
The second stage was pressurized with nitrogen gas to 60-psi and did not contain any fuel or oxidizer.
A follow-up test 6 days later was conducted on a scrapped Thor IRBM, its remnants reside at the SLC-10 Museum at Vandenberg AFB.
When the storable-fueled Titan II and the solid-fueled Minuteman I were deployed in 1963, the Titan I and Atlas missiles became obsolete. They were retired from service as ICBMs in early 1965.
The final launch from Vandenberg Air Force Base (VAFB) occurred on 5 March 1965. At that time, the disposition of the 101 total production missiles was as follows:
17 were test launched from VAFB (September 1961 – March 1965)
one was destroyed in Beale AFB Site 851-C1 silo explosion 24 May 1962
54 were deployed in silos on 20 January 1965
29 were in storage at SBAMA
(three at VAFB, one at each of five bases, one at Lowry, and 20 in storage at SBAMA elsewhere)
The 83 surplus missiles remained in inventory at Mira Loma AFS. It did not make economic sense to refurbish them as SM-65 Atlas missiles with similar payload capacities had already been converted to satellite launchers. About 33 were distributed to museums, parks and schools as static displays (see list below).  The remaining 50 missiles were scrapped at Mira Loma AFS near San Bernardino, CA; the last was broken up in 1972, in accordance with the SALT-I Treaty of 1 February 1972. 
By November 1965 the Air Force Logistics Command had determined that the cost of modifying the widely dispersed sites to support other ballistic missiles was prohibitive, and attempts were made to find new uses. By Spring 1966 a number of possible uses and users had been identified. By 6 May 1966 the Air Force wanted to retain 5 Titan sites and the General Services Administration had earmarked 1 for possible use. The USAF removed equipment it had uses for, the rest was offered to other government agencies. Eventually no sites were retained and all were salvaged. The chosen method was the Service and Salvage contract, which required the contractor to remove the equipment the government wanted before proceeding with scrapping. This accounts for the varied degree of salvage at the sites today. Most are sealed today, with one in Colorado that is easily entered but also very unsafe. One is open for tours.
Most of the ATHENA guidance computers were given to universities. One is in the Smithsonian. One remained in use at Vandenberg AFB until it guided a last Thor-Agena launch in May 1972. It had guided over 400 missiles.
On 6 September 1985 Strategic Defense Initiative (AKA "Star Wars" program), a scrapped Titan I Second Stage was used in a Missile Defense test. The MIRACL Near Infrared Laser, at White Sands Missile Range, NM was fired at a stationary Titan I second stage that was fixed to the ground. The second stage burst and was destroyed by the laser blast. The second stage was pressurized with nitrogen gas to 60-psi and did not contain any fuel or oxidizer. A follow-up test 6 days later was conducted on a scrapped Thor IRBM, its remnants reside at the SLC-10 Museum at Vandenberg AFB.
HGM-25A Titan I