Click photos to see explanation and enlarge the photo.
| 1954, December | Business Approval for Onioshidashi area. |
|---|---|
| 1960 | Asama ranch parking area completed. |
| 1961 | Asama Line (municipal road) construction begins. |
| 1962 | Asama-en parking area completed. |
| 1963 | Nature study road, Onioshi bridge, Asama bridge, management office and 7 stores completed. |
| August 8th | Opening ceremony |
| 1964, April | Construction of observation deck and museum begins. |
| 1967, April 18th | Inauguration and opening ceremony |
| April 19th | Start of commercial operation. |
| June 12th | Visit by seismic researchers from 11 countries. |
| July 21st | Visit by governor of Gunma prefecture. |
| 1968, August 30th | Visit by imperial prince Hironomiya. |
| 1969, August 1st | Camp site opens. |
| August 19th | Visit by minister of finance. |
| 1970, July 8th | Visit by Japan Small Scale Water Works Association |
| October 9th | Park monument installed Visit by seismic researchers from 11 countries |
| 1972, June 26th | Paving of Asama line completed. |
| August 31st | Visit by imperial prince. |
| 1973, February 1st | Eruption of Mt. Asama. |
| May 22nd | Asama seismometer observations begin. |
| August 20th | Seven shelters installed. |
| August 26th | Wireless radio station installed. |
| 1974, April 20th | Museum improvement work started. |
| 1975, April 1st | Entrance price revised from 100yen to 300yen. |
| December 25th | Construction of shopping area. |
| 1977, March 25th | Refurbishment of viewpoint area (museum extension and office relocation) |
| July 30th | Viewpoint construction(iron and wood). |
| August | 10 year anniversary ceremony. |
| 1978, May 31st | Construction to extend museum exhibition area. |
| 1979, July 15th | Construction to extend museum exhibition area. |
| December 22nd | Family ski area construction. (Landscaping, ski-lift, electrical installation) |
| 1980, June 30th | Lawn extended. (Landscaping, planting, water supply work) |
| 1981, August 9th | 1st Asappu concert(2,000 attendees) |
| 1982, April 26th | Early morning eruption of Mt. Asama. |
| August 1st | 2nd Asappu concert.(1,000 attendees) |
| October,2nd | Small eruption. |
| 1983, April 26th | Early morning eruption of Mt. Asama. |
| August | 3rd Asappu concert. |
| 1984, July 31st | 4th Asappu concert. |
| 1985, June 30th | Reconstruction of entrance hall. (Fire alarms installed, 162㎡.) |
| 1986, July 20th | Video projector system completed. |
| 1987, July 31st | Reconstruction of camp site. |
| 1988, December 29th | Automated fire alarm improvements. |
| 1989, June 1st | Asama memorial hall opens,revised entrance price revised from 300yen to 500yen. |
| 1990, December 15th | Electrical construction and snow machine installed. (600v,150 buried) |
| 1991, October 30th | Survey the land form. |
| 1992, August 20th | Renovation of museum, restaurant, and shops starts. |
| 1993, April 30th | Renovation of museum, restaurant, and shops finished. |
| June 20th | Surveillance camera installed. |
| June 26th | Inauguration ceremony of Asama volcano museum. Visit by imperial prince Akisinonomiya and his wife. |
| July 1st | Asama volcano museum, restaurant, and shops reopen. |
| October 1st | Explanation panels installed on nature study road. |
| 1994, August 11th | Free rest area opened. |
| 1996, March 31st | Basic business plan of Asama-en decided. |
| August 5th | Exhibition: “Excavation of Tenmei-era agricultural community”(until 25th) |
| August 7th | Asama volcano forum. |
| August 8th | 30 year anniversary ceremony. |
| 2016, September | Asama north area certificated as Japanese geopark. Becomes visitor center. |
