Annual report pursuant to Section 13 and 15(d)

Schedule III - Real Estate and Accumulated Depreciation

v3.20.4
Schedule III - Real Estate and Accumulated Depreciation
 12 Months Ended
Dec. 31, 2020
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation Disclosure [Abstract]  
Schedule III-Real Estate and Accumulated Depreciation
Initial Cost Gross Amounts Carried
At Close of Period
Property (Type) (1) Location Encumbrances (2) Land Building
and Land Improvements		 Costs Capitalized Subsequent to Acquisition Land Building
and Land Improvements		 Total
(3)		 Accumulated Depreciation (4) Year Built or Renovated Date Acquired (5)
100 Light Street (O) Baltimore, MD $ 46,543  $ 26,715  $ 58,002  $ 21,859  $ 26,715  $ 79,861  $ 106,576  $ (20,981) 1973/2011 8/7/2015
100 Secured Gateway (O) Huntsville, AL —  —  70,552  —  —  70,552  70,552  (566) 2020 3/23/2010
1000 Redstone Gateway (O) Huntsville, AL 9,666  —  20,533  65  —  20,598  20,598  (4,007) 2013 3/23/2010
1100 Redstone Gateway (O) Huntsville, AL 10,263  —  19,593  66  —  19,659  19,659  (3,418) 2014 3/23/2010
114 National Business Parkway (O) Annapolis Junction, MD —  364  3,109  302  364  3,411  3,775  (1,584) 2002 6/30/2000
1200 Redstone Gateway (O) Huntsville, AL 11,851  —  22,389  60  —  22,449  22,449  (3,945) 2013 3/23/2010
1201 M Street SE (O) Washington, DC —  —  49,785  9,621  —  59,406  59,406  (19,011) 2001 9/28/2010
1201 Winterson Road (O) Linthicum, MD —  2,130  17,007  901  2,130  17,908  20,038  (5,506) 1985/2017 4/30/1998
1220 12th Street SE (O) Washington, DC —  —  42,464  8,795  —  51,259  51,259  (17,812) 2003 9/28/2010
1243 Winterson Road (L) Linthicum, MD —  630  —  —  630  —  630  —  (6) 12/19/2001
131 National Business Parkway (O) Annapolis Junction, MD —  1,906  7,623  5,075  1,906  12,698  14,604  (7,442) 1990 9/28/1998
132 National Business Parkway (O) Annapolis Junction, MD —  2,917  12,259  4,730  2,917  16,989  19,906  (10,566) 2000 5/28/1999
133 National Business Parkway (O) Annapolis Junction, MD —  2,517  10,068  6,274  2,517  16,342  18,859  (10,443) 1997 9/28/1998
134 National Business Parkway (O) Annapolis Junction, MD —  3,684  7,517  5,007  3,684  12,524  16,208  (7,329) 1999 11/13/1998
1340 Ashton Road (O) Hanover, MD —  905  3,620  2,042  905  5,662  6,567  (3,255) 1989 4/28/1999
13450 Sunrise Valley Drive (O) Herndon, VA —  1,386  5,576  4,636  1,386  10,212  11,598  (6,156) 1998 7/25/2003
13454 Sunrise Valley Drive (O) Herndon, VA —  2,847  11,986  9,184  2,847  21,170  24,017  (12,075) 1998 7/25/2003
135 National Business Parkway (O) Annapolis Junction, MD —  2,484  9,750  6,528  2,484  16,278  18,762  (10,164) 1998 12/30/1998
1362 Mellon Road (O) Hanover, MD —  950  3,864  1,065  950  4,929  5,879  (854) 2006 2/10/2006
13857 McLearen Road (O) Herndon, VA —  3,507  30,177  4,915  3,507  35,092  38,599  (12,784) 2007 7/11/2012
140 National Business Parkway (O) Annapolis Junction, MD —  3,407  24,167  1,751  3,407  25,918  29,325  (10,941) 2003 12/31/2003
141 National Business Parkway (O) Annapolis Junction, MD —  2,398  9,538  4,832  2,398  14,370  16,768  (9,190) 1990 9/28/1998
14280 Park Meadow Drive (O) Chantilly, VA —  3,731  15,953  5,485  3,731  21,438  25,169  (9,512) 1999 9/29/2004
1460 Dorsey Road (L) Hanover, MD —  1,577  76  —  1,577  76  1,653  —  (6) 2/28/2006
14840 Conference Center Drive (O) Chantilly, VA —  1,572  8,175  5,751  1,572  13,926  15,498  (7,351) 2000 7/25/2003
14850 Conference Center Drive (O) Chantilly, VA —  1,615  8,358  3,873  1,615  12,231  13,846  (7,115) 2000 7/25/2003
14900 Conference Center Drive (O) Chantilly, VA —  3,436  14,402  8,659  3,436  23,061  26,497  (13,126) 1999 7/25/2003
1501 South Clinton Street (O) Baltimore, MD —  27,964  51,990  20,656  27,964  72,646  100,610  (28,175) 2006 10/27/2009
15049 Conference Center Drive (O) Chantilly, VA —  4,415  20,365  17,851  4,415  38,216  42,631  (18,061) 1997 8/14/2002
15059 Conference Center Drive (O) Chantilly, VA —  5,753  13,615  4,386  5,753  18,001  23,754  (10,079) 2000 8/14/2002
1550 West Nursery Road (O) Linthicum, MD —  14,071  16,930  —  14,071  16,930  31,001  (6,310) 2009 10/28/2009
1560 West Nursery Road (O) Linthicum, MD —  1,441  113  —  1,441  113  1,554  (19) 2014 10/28/2009
1610 West Nursery Road (O) Linthicum, MD —  259  246  —  259  246  505  (23) 2016 4/30/1998
1616 West Nursery Road (O) Linthicum, MD —  393  3,323  75  393  3,398  3,791  (268) 2017 4/30/1998
1622 West Nursery Road (O) Linthicum, MD —  393  2,542  —  393  2,542  2,935  (244) 2016 4/30/1998
16442 Commerce Drive (O) Dahlgren, VA —  613  2,582  980  613  3,562  4,175  (1,860) 2002 12/21/2004
Initial Cost Gross Amounts Carried
At Close of Period
Property (Type) (1) Location Encumbrances (2) Land Building
and Land Improvements		 Costs Capitalized Subsequent to Acquisition Land Building
and Land Improvements		 Total
(3)		 Accumulated Depreciation (4) Year Built or Renovated Date Acquired (5)
16480 Commerce Drive (O) Dahlgren, VA —  1,856  7,425  2,602  1,856  10,027  11,883  (4,274) 2000 12/28/2004
16501 Commerce Drive (O) Dahlgren, VA —  522  2,090  1,040  522  3,130  3,652  (1,399) 2002 12/21/2004
16539 Commerce Drive (O) Dahlgren, VA —  688  2,860  2,326  688  5,186  5,874  (2,879) 1990 12/21/2004
16541 Commerce Drive (O) Dahlgren, VA —  773  3,094  2,594  773  5,688  6,461  (2,696) 1996 12/21/2004
16543 Commerce Drive (O) Dahlgren, VA —  436  1,742  838  436  2,580  3,016  (1,231) 2002 12/21/2004
1751 Pinnacle Drive (O) McLean, VA —  10,486  42,339  33,689  10,486  76,028  86,514  (38,872) 1989/1995 9/23/2004
1753 Pinnacle Drive (O) McLean, VA —  8,275  34,353  23,954  8,275  58,307  66,582  (25,248) 1976/2004 9/23/2004
206 Research Boulevard (O) Aberdeen, MD —  —  —  —  —  —  —  (1) 2012 9/14/2007
209 Research Boulevard (O) Aberdeen, MD —  134  1,711  327  134  2,038  2,172  (599) 2010 9/14/2007
210 Research Boulevard (O) Aberdeen, MD —  113  1,402  248  113  1,650  1,763  (493) 2010 9/14/2007
2100 L Street (O) Washington, DC 82,882  19,024  92,387  —  19,024  92,387  111,411  —  2020 (7) 8/11/2015
2100 Rideout Road (O) Huntsville, AL —  —  7,347  2,995  —  10,342  10,342  (1,786) 2016 3/23/2010
22289 Exploration Drive (O) Lexington Park, MD —  1,422  5,719  2,061  1,422  7,780  9,202  (4,126) 2000 3/24/2004
22299 Exploration Drive (O) Lexington Park, MD —  1,362  5,791  2,994  1,362  8,785  10,147  (4,888) 1998 3/24/2004
22300 Exploration Drive (O) Lexington Park, MD —  1,094  5,038  2,770  1,094  7,808  8,902  (3,624) 1997 11/9/2004
22309 Exploration Drive (O) Lexington Park, MD —  2,243  10,419  8,205  2,243  18,624  20,867  (8,227) 1984/1997 3/24/2004
23535 Cottonwood Parkway (O) California, MD —  692  3,051  648  692  3,699  4,391  (2,027) 1984 3/24/2004
250 W Pratt St (O) Baltimore, MD —  8,057  34,588  16,213  8,057  50,801  58,858  (15,418) 1985 3/19/2015
2500 Riva Road (O) Annapolis, MD —  2,791  12,155  1  2,791  12,156  14,947  (12,146) 2000 3/4/2003
2600 Park Tower Drive (O) Vienna, VA —  20,284  34,443  3,883  20,284  38,326  58,610  (7,108) 1999 4/15/2015
2691 Technology Drive (O) Annapolis Junction, MD —  2,098  17,334  5,565  2,098  22,899  24,997  (11,747) 2005 5/26/2000
2701 Technology Drive (O) Annapolis Junction, MD —  1,737  15,266  5,629  1,737  20,895  22,632  (12,487) 2001 5/26/2000
2711 Technology Drive (O) Annapolis Junction, MD —  2,251  21,611  4,332  2,251  25,943  28,194  (13,586) 2002 11/13/2000
2720 Technology Drive (O) Annapolis Junction, MD —  3,863  29,272  2,796  3,863  32,068  35,931  (13,249) 2004 1/31/2002
2721 Technology Drive (O) Annapolis Junction, MD —  4,611  14,597  3,247  4,611  17,844  22,455  (10,267) 2000 10/21/1999
2730 Hercules Road (O) Annapolis Junction, MD —  8,737  31,612  8,726  8,737  40,338  49,075  (22,740) 1990 9/28/1998
30 Light Street (O) Baltimore, MD 3,915  —  12,101  1,009  —  13,110  13,110  (1,894) 2009 8/7/2015
300 Sentinel Drive (O) Annapolis Junction, MD —  1,517  59,165  2,095  1,517  61,260  62,777  (16,564) 2009 11/14/2003
302 Sentinel Drive (O) Annapolis Junction, MD —  2,648  29,687  1,094  2,648  30,781  33,429  (10,028) 2007 11/14/2003
304 Sentinel Drive (O) Annapolis Junction, MD —  3,411  24,917  1,982  3,411  26,899  30,310  (11,186) 2005 11/14/2003
306 Sentinel Drive (O) Annapolis Junction, MD —  3,260  22,592  2,566  3,260  25,158  28,418  (9,147) 2006 11/14/2003
308 Sentinel Drive (O) Annapolis Junction, MD —  1,422  26,208  2,354  1,422  28,562  29,984  (7,003) 2010 11/14/2003
310 Sentinel Way (O) Annapolis Junction, MD —  2,372  42,584  —  2,372  42,584  44,956  (5,027) 2016 11/14/2003
310 The Bridge Street (O) Huntsville, AL —  261  26,531  5,135  261  31,666  31,927  (11,066) 2009 8/9/2011
312 Sentinel Way (O) Annapolis Junction, MD —  3,138  27,797  —  3,138  27,797  30,935  (4,389) 2014 11/14/2003
314 Sentinel Way (O) Annapolis Junction, MD —  1,254  7,741  —  1,254  7,741  8,995  (1,247) 2008 11/14/2003
Initial Cost Gross Amounts Carried
At Close of Period
Property (Type) (1) Location Encumbrances (2) Land Building
and Land Improvements		 Costs Capitalized Subsequent to Acquisition Land Building
and Land Improvements		 Total
(3)		 Accumulated Depreciation (4) Year Built or Renovated Date Acquired (5)
316 Sentinel Way (O) Annapolis Junction, MD —  2,748  38,156  226  2,748  38,382  41,130  (8,426) 2011 11/14/2003
318 Sentinel Way (O) Annapolis Junction, MD —  2,185  28,426  560  2,185  28,986  31,171  (10,716) 2005 11/14/2003
320 Sentinel Way (O) Annapolis Junction, MD —  2,067  21,623  132  2,067  21,755  23,822  (7,029) 2007 11/14/2003
322 Sentinel Way (O) Annapolis Junction, MD —  2,605  22,827  1,900  2,605  24,727  27,332  (8,568) 2006 11/14/2003
324 Sentinel Way (O) Annapolis Junction, MD —  1,656  23,018  38  1,656  23,056  24,712  (5,956) 2010 6/29/2006
4000 Market Street (O) Huntsville, AL 6,052  —  9,207  —  —  9,207  9,207  (394) 2018 3/23/2010
410 National Business Parkway (O) Annapolis Junction, MD —  1,831  23,257  2,080  1,831  25,337  27,168  (5,032) 2012 6/29/2006
4100 Market Street (O) Huntsville, AL 5,269  —  8,020  —  —  8,020  8,020  (304) 2019 3/23/2010
420 National Business Parkway (O) Annapolis Junction, MD —  2,370  27,751  148  2,370  27,899  30,269  (4,752) 2013 6/29/2006
430 National Business Parkway (O) Annapolis Junction, MD —  1,852  21,563  830  1,852  22,393  24,245  (4,936) 2011 6/29/2006
44408 Pecan Court (O) California, MD —  817  1,583  1,706  817  3,289  4,106  (1,679) 1986 3/24/2004
44414 Pecan Court (O) California, MD —  405  1,619  1,138  405  2,757  3,162  (1,512) 1986 3/24/2004
44417 Pecan Court (O) California, MD —  434  3,822  180  434  4,002  4,436  (2,005) 1989/2015 3/24/2004
44420 Pecan Court (O) California, MD —  344  890  291  344  1,181  1,525  (546) 1989 11/9/2004
44425 Pecan Court (O) California, MD —  1,309  3,506  2,349  1,309  5,855  7,164  (3,431) 1997 5/5/2004
45310 Abell House Lane (O) California, MD —  2,272  13,808  816  2,272  14,624  16,896  (3,455) 2011 8/30/2010
4600 River Road (O) College Park, MD —  —  23,294  —  —  23,294  23,294  (19) 2020 (7) 1/29/2008
46579 Expedition Drive (O) Lexington Park, MD —  1,406  5,796  2,712  1,406  8,508  9,914  (4,231) 2002 3/24/2004
46591 Expedition Drive (O) Lexington Park, MD —  1,200  7,199  3,399  1,200  10,598  11,798  (3,932) 2005 3/24/2004
4851 Stonecroft Boulevard (O) Chantilly, VA —  1,878  11,558  299  1,878  11,857  13,735  (4,697) 2004 8/14/2002
540 National Business Parkway (O) Annapolis Junction, MD —  2,035  31,249  9  2,035  31,258  33,293  (2,521) 2017 6/29/2006
5520 Research Park Drive (O) Catonsville, MD —  —  20,072  1,641  —  21,713  21,713  (6,375) 2009 4/4/2006
5522 Research Park Drive (O) Catonsville, MD —  —  4,550  855  —  5,405  5,405  (1,652) 2007 3/8/2006
5801 University Research Court (O) College Park, MD 11,200  —  17,434  —  —  17,434  17,434  (1,195) 2018 1/29/2008
5825 University Research Court (O) College Park, MD 20,011  —  22,771  1,780  —  24,551  24,551  (7,170) 2008 1/29/2008
5850 University Research Court (O) College Park, MD 21,171  —  31,906  405  —  32,311  32,311  (8,885) 2008 1/29/2008
6000 Redstone Gateway (O) Huntsville, AL —  —  8,268  —  —  8,268  8,268  (14) 2020 (7) 3/23/2010
610 Guardian Way (O) Annapolis Junction, MD —  6,946  14,597  —  6,946  14,597  21,543  —  (7) 6/29/2006
6700 Alexander Bell Drive (O) Columbia, MD —  1,755  7,019  8,788  1,755  15,807  17,562  (8,825) 1988 5/14/2001
6708 Alexander Bell Drive (O) Columbia, MD —  897  12,644  1,618  897  14,262  15,159  (4,674) 1988/2016 5/14/2001
6711 Columbia Gateway Drive (O) Columbia, MD —  2,683  23,239  1,557  2,683  24,796  27,479  (9,200) 2006-2007 9/28/2000
6716 Alexander Bell Drive (O) Columbia, MD —  1,242  4,969  4,672  1,242  9,641  10,883  (6,123) 1990 12/31/1998
6721 Columbia Gateway Drive (O) Columbia, MD —  1,753  34,090  2,391  1,753  36,481  38,234  (10,096) 2009 9/28/2000
6724 Alexander Bell Drive (O) Columbia, MD —  449  5,039  2,507  449  7,546  7,995  (3,592) 2001 5/14/2001
6731 Columbia Gateway Drive (O) Columbia, MD —  2,807  19,098  5,605  2,807  24,703  27,510  (13,179) 2002 3/29/2000
6740 Alexander Bell Drive (O) Columbia, MD —  1,424  5,696  3,466  1,424  9,162  10,586  (6,236) 1992 12/31/1998
Initial Cost Gross Amounts Carried
At Close of Period
Property (Type) (1) Location Encumbrances (2) Land Building
and Land Improvements		 Costs Capitalized Subsequent to Acquisition Land Building
and Land Improvements		 Total
(3)		 Accumulated Depreciation (4) Year Built or Renovated Date Acquired (5)
6741 Columbia Gateway Drive (O) Columbia, MD —  675  1,711  169  675  1,880  2,555  (639) 2008 9/28/2000
6750 Alexander Bell Drive (O) Columbia, MD —  1,263  12,461  5,075  1,263  17,536  18,799  (10,635) 2001 12/31/1998
6760 Alexander Bell Drive (O) Columbia, MD —  890  3,561  3,920  890  7,481  8,371  (4,859) 1991 12/31/1998
6940 Columbia Gateway Drive (O) Columbia, MD —  3,545  9,916  8,739  3,545  18,655  22,200  (10,795) 1999 11/13/1998
6950 Columbia Gateway Drive (O) Columbia, MD —  3,596  27,723  3,223  3,596  30,946  34,542  (11,991) 1998/2019 10/22/1998
7000 Columbia Gateway Drive (O) Columbia, MD —  3,131  12,103  7,537  3,131  19,640  22,771  (9,679) 1999 5/31/2002
7005 Columbia Gateway Drive (L) Columbia, MD —  3,036  747  —  3,036  747  3,783  —  (6) 6/26/2014
7015 Albert Einstein Drive (O) Columbia, MD —  2,058  6,093  3,319  2,058  9,412  11,470  (4,585) 1999 12/1/2005
7061 Columbia Gateway Drive (O) Columbia, MD —  729  3,094  2,640  729  5,734  6,463  (3,393) 2000 8/30/2001
7063 Columbia Gateway Drive (O) Columbia, MD —  902  3,684  3,468  902  7,152  8,054  (4,450) 2000 8/30/2001
7065 Columbia Gateway Drive (O) Columbia, MD —  919  3,763  3,097  919  6,860  7,779  (4,565) 2000 8/30/2001
7067 Columbia Gateway Drive (O) Columbia, MD —  1,829  11,823  5,404  1,829  17,227  19,056  (8,693) 2001 8/30/2001
7100 Redstone Gateway (O) Huntsville, AL —  —  9,101  —  —  9,101  9,101  —  (7) 3/23/2010
7125 Columbia Gateway Drive (O) Columbia, MD —  20,487  47,029  23,580  20,487  70,609  91,096  (27,691) 1973/1999 6/29/2006
7130 Columbia Gateway Drive (O) Columbia, MD —  1,350  4,359  2,896  1,350  7,255  8,605  (3,848) 1989 9/19/2005
7134 Columbia Gateway Drive (O) Columbia, MD —  704  4,700  668  704  5,368  6,072  (1,803) 1990/2016 9/19/2005
7138 Columbia Gateway Drive (O) Columbia, MD —  1,104  3,518  2,853  1,104  6,371  7,475  (4,072) 1990 9/19/2005
7142 Columbia Gateway Drive (O) Columbia, MD —  1,342  7,148  2,611  1,342  9,759  11,101  (4,052) 1994/2018 9/19/2005
7150 Columbia Gateway Drive (O) Columbia, MD —  1,032  3,429  813  1,032  4,242  5,274  (1,789) 1991 9/19/2005
7150 Riverwood Drive (O) Columbia, MD —  1,821  4,388  1,850  1,821  6,238  8,059  (3,016) 2000 1/10/2007
7160 Riverwood Drive (O) Columbia, MD —  2,732  7,006  4,405  2,732  11,411  14,143  (4,768) 2000 1/10/2007
7170 Riverwood Drive (O) Columbia, MD —  1,283  3,096  2,281  1,283  5,377  6,660  (2,576) 2000 1/10/2007
7175 Riverwood Drive (O) Columbia, MD —  1,788  7,269  —  1,788  7,269  9,057  (1,298) 1996/2013 7/27/2005
7200 Redstone Gateway (O) Huntsville, AL —  —  8,348  81  —  8,429  8,429  (1,393) 2013 3/23/2010
7200 Riverwood Drive (O) Columbia, MD —  4,089  22,630  4,634  4,089  27,264  31,353  (12,592) 1986 10/13/1998
7205 Riverwood Drive (O) Columbia, MD —  1,367  21,419  —  1,367  21,419  22,786  (3,987) 2013 7/27/2005
7272 Park Circle Drive (O) Hanover, MD —  1,479  6,300  4,608  1,479  10,908  12,387  (5,467) 1991/1996 1/10/2007
7318 Parkway Drive (O) Hanover, MD —  972  3,888  1,324  972  5,212  6,184  (2,929) 1984 4/16/1999
7400 Redstone Gateway (O) Huntsville, AL —  —  9,223  75  —  9,298  9,298  (1,281) 2015 3/23/2010
7467 Ridge Road (O) Hanover, MD —  1,565  3,116  5,041  1,565  8,157  9,722  (4,110) 1990 4/28/1999
7500 Advanced Gateway (O) Huntsville, AL —  —  19,070  —  —  19,070  19,070  (264) 2020 3/23/2010
7600 Advanced Gateway (O) Huntsville, AL —  —  14,126  —  —  14,126  14,126  (135) 2020 3/23/2010
7740 Milestone Parkway (O) Hanover, MD 16,902  3,825  34,176  1,084  3,825  35,260  39,085  (9,279) 2009 7/2/2007
7770 Backlick Road (O) Springfield, VA —  6,387  78,779  1,531  6,387  80,310  86,697  (14,971) 2012 3/10/2010
7880 Milestone Parkway (O) Hanover, MD —  4,857  25,916  321  4,857  26,237  31,094  (3,384) 2015 9/17/2013
8000 Rideout Road (O) Huntsville, AL —  —  16,138  —  —  16,138  16,138  —  (7) 3/23/2010
Initial Cost Gross Amounts Carried
At Close of Period
Property (Type) (1) Location Encumbrances (2) Land Building
and Land Improvements		 Costs Capitalized Subsequent to Acquisition Land Building
and Land Improvements		 Total
(3)		 Accumulated Depreciation (4) Year Built or Renovated Date Acquired (5)
8600 Advanced Gateway (O) Huntsville, AL —  —  25,168  —  —  25,168  25,168  (45) 2020 3/23/2010
8621 Robert Fulton Drive (O) Columbia, MD —  2,317  12,642  6,191  2,317  18,833  21,150  (6,700) 2005-2006 6/10/2005
8661 Robert Fulton Drive (O) Columbia, MD —  1,510  3,764  3,019  1,510  6,783  8,293  (3,528) 2002 12/30/2003
8671 Robert Fulton Drive (O) Columbia, MD —  1,718  4,280  4,294  1,718  8,574  10,292  (4,716) 2002 12/30/2003
870 Elkridge Landing Road (O) Linthicum, MD —  2,003  9,442  10,464  2,003  19,906  21,909  (11,574) 1981 8/3/2001
8800 Redstone Gateway (O) Huntsville, AL 11,679  —  18,446  —  —  18,446  18,446  (511) 2019 3/23/2010
891 Elkridge Landing Road (O) Linthicum, MD —  1,165  4,772  3,512  1,165  8,284  9,449  (5,193) 1984 7/2/2001
901 Elkridge Landing Road (O) Linthicum, MD —  1,156  4,437  4,789  1,156  9,226  10,382  (4,687) 1984 7/2/2001
911 Elkridge Landing Road (O) Linthicum, MD —  1,215  4,861  3,431  1,215  8,292  9,507  (4,786) 1985 4/30/1998
938 Elkridge Landing Road (O) Linthicum, MD —  922  4,748  1,516  922  6,264  7,186  (3,221) 1984 7/2/2001
939 Elkridge Landing Road (O) Linthicum, MD —  939  3,756  4,444  939  8,200  9,139  (5,388) 1983 4/30/1998
9651 Hornbaker Road (D) Manassas, VA —  6,050  250,355  16,105  6,050  266,460  272,510  (72,246) 2010 9/14/2010
Arundel Preserve (L) Hanover, MD —  13,352  9,699  —  13,352  9,699  23,051  —  (6) 7/2/2007
Canton Crossing Land (L) Baltimore, MD —  17,285  8,363  142  17,285  8,505  25,790  —  (6) 10/27/2009
Canton Crossing Util Distr Ctr (O) Baltimore, MD —  6,100  10,450  1,689  6,100  12,139  18,239  (6,269) 2006 10/27/2009
Columbia Gateway - Southridge (L) Columbia, MD —  6,387  3,722  —  6,387  3,722  10,109  —  (6) 9/20/2004
Dahlgren Technology Center (L) Dahlgren, VA —  978  178  —  978  178  1,156  —  (6) 3/16/2005
Expedition VII (O) Lexington Park, MD —  705  862  —  705  862  1,567  —  (7) 3/24/2004
IN 1 (O) Northern Virginia —  1,815  15,972  —  1,815  15,972  17,787  (735) 2019 8/31/2016
IN 2 (O) Northern Virginia —  2,627  28,829  —  2,627  28,829  31,456  (1,081) 2019 8/31/2016
M Square Research Park (L) College Park, MD —  —  2,020  —  —  2,020  2,020  —  (6) 1/29/2008
MP 1 (O) Northern Virginia —  9,426  30,924  —  9,426  30,924  40,350  (1,240) 2019 11/20/2017
MP 2 (O) Northern Virginia —  9,426  29,989  —  9,426  29,989  39,415  (1,416) 2018 11/20/2017
MR Land (L) Northern Virginia —  9,038  514  —  9,038  514  9,552  —  (6) 11/8/2018
National Business Park North (L) Annapolis Junction, MD —  21,898  35,639  —  21,898  35,639  57,537  —  (6) 6/29/2006
North Gate Business Park (L) Aberdeen, MD —  1,755  5  —  1,755  5  1,760  —  (6) 9/14/2007
NoVA Office A (O) (8) Chantilly, VA —  2,096  46,849  10  2,096  46,859  48,955  (6,926) 2015 7/18/2002
NoVA Office B (O) (8) Chantilly, VA —  739  38,376  —  739  38,376  39,115  (3,734) 2016 7/18/2002
NoVA Office C (O) (8) Chantilly, VA —  5,604  48,235  —  5,604  48,235  53,839  —  (7) 7/18/2002
NoVA Office D (O) (8) Chantilly, VA —  6,587  40,559  —  6,587  40,559  47,146  (3,450) 2017 7/2/2013
Oak Grove A (O) Northern Virginia —  12,866  34,427  —  12,866  34,427  47,293  (494) 2020 11/1/2018
Oak Grove B (O) Northern Virginia —  12,866  40,550  —  12,866  40,550  53,416  (811) 2019 11/1/2018
Oak Grove Phase II (L) Northern Virginia —  23,483  8,833  —  23,483  8,833  32,316  —  (6) 11/1/2018
Old Annapolis Road (O) Columbia, MD —  1,637  5,500  6,710  1,637  12,210  13,847  (4,870) 1974/1985 12/14/2000
P2 A (O) Northern Virginia —  16,878  39,934  —  16,878  39,934  56,812  (738) 2020 5/2/2019
P2 B (O) Northern Virginia —  22,866  35,960  —  22,866  35,960  58,826  (292) 2020 5/2/2019
Initial Cost Gross Amounts Carried
At Close of Period
Property (Type) (1) Location Encumbrances (2) Land Building
and Land Improvements		 Costs Capitalized Subsequent to Acquisition Land Building
and Land Improvements		 Total
(3)		 Accumulated Depreciation (4) Year Built or Renovated Date Acquired (5)
P2 C (O) Northern Virginia —  14,842  30,272  —  14,842  30,272  45,114  (60) 2020 5/2/2019
Paragon Park (L) Northern Virginia —  7,738  462  —  7,738  462  8,200  —  (6) 5/8/2017
Parkstone A (O) Northern Virginia —  3,942  1,257  —  3,942  1,257  5,199  —  (7) 1/27/2005
Parkstone B (O) Northern Virginia —  3,346  1,074  —  3,346  1,074  4,420  —  (7) 1/27/2005
Patriot Ridge (L) Springfield, VA —  18,517  14,562  —  18,517  14,562  33,079  —  (6) 3/10/2010
Project EL (O) Confidential-USA —  7,430  7,479  —  7,430  7,479  14,909  —  (7) 1/20/2006
Project EX (O) (9) Confidential-USA —  8,959  16,981  —  8,959  16,981  25,940  (698) 2018 7/16/2008
Redstone Gateway (L) Huntsville, AL —  —  33,310  —  —  33,310  33,310  (5) (6) 3/23/2010
Sentry Gateway (L) San Antonio, TX —  4,052  1,833  —  4,052  1,833  5,885  —  (6) 3/30/2005
Sentry Gateway - T (O) San Antonio, TX —  14,020  38,804  13  14,020  38,817  52,837  (13,473) 1982/2008 3/30/2005
Sentry Gateway - V (O) San Antonio, TX —  —  1,066  —  —  1,066  1,066  (321) 2007 3/30/2005
Sentry Gateway - W (O) San Antonio, TX —  —  1,884  71  —  1,955  1,955  (548) 2009 3/30/2005
Sentry Gateway - X (O) San Antonio, TX —  1,964  21,178  —  1,964  21,178  23,142  (5,375) 2010 1/20/2006
Sentry Gateway - Y (O) San Antonio, TX —  1,964  21,298  —  1,964  21,298  23,262  (5,407) 2010 1/20/2006
Sentry Gateway - Z (O) San Antonio, TX —  1,964  30,573  —  1,964  30,573  32,537  (4,438) 2015 6/14/2005
SP Manassas (L) Manassas, VA —  8,156  187  —  8,156  187  8,343  —  (6) 7/24/2019
Westfields - Park Center (L) Chantilly, VA —  10,815  6,206  —  10,815  6,206  17,021  —  (6) 7/2/2013
Other Developments, including intercompany eliminations (V) Various —  —  282  257  —  539  539  (90) Various Various
$ 257,404  $ 712,057  $ 3,427,401  $ 547,344  $ 712,057  $ 3,974,745  $ 4,686,802  $ (1,124,253)
(1)A legend for the Property Type follows: (O) = Office or Data Center Shell Property; (L) = Land held or pre-development; (D) = Wholesale Data Center; and (V) = Various.
(2)Excludes our Revolving Credit Facility of $143.0 million, term loan facilities of $398.4 million, unsecured senior notes of $1.3 billion, unsecured notes payable of $900,000, and deferred financing costs, net of premiums, on the remaining loans of $2.3 million.
(3)The aggregate cost of these assets for Federal income tax purposes was approximately $3.6 billion as of December 31, 2020.
(4)The estimated lives over which depreciation is recognized follow: Building and land improvements: 10-40 years; and tenant improvements: related lease terms.
(5)The acquisition date of multi-parcel properties reflects the date of the earliest parcel acquisition. The acquisition date of properties owned through real estate joint ventures reflects the date of the formation of the joint venture.
(6)Held as of December 31, 2020.
(7)Under development or redevelopment as of December 31, 2020.
(8)The carrying amounts of these properties exclude allocated costs of the garage being constructed to support the properties.
(9)This property represents land under a long-term contract.
The following table summarizes our changes in cost of properties for the years ended December 31, 2020, 2019 and 2018 (in thousands):
2020 2019 2018
Beginning balance $ 4,348,006  $ 4,148,529  $ 3,980,813 
Improvements and other additions 405,940  480,418  224,524 
Sales (1) (65,475) (242,497) (53,547)
Impairments (1,530) (329) (2,493)
Other dispositions (139) (340) (768)
Reclassification to right-of use asset —  (37,775) — 
Ending balance $ 4,686,802  $ 4,348,006  $ 4,148,529 
The following table summarizes our changes in accumulated depreciation for the same time periods (in thousands):
2020 2019 2018
Beginning balance $ 1,007,120  $ 897,903  $ 801,038 
Depreciation expense 119,377  117,973  112,610 
Sales (1) (2,105) (8,416) (14,845)
Impairments —  —  (132)
Other dispositions (139) (340) (768)
Ending balance $ 1,124,253  $ 1,007,120  $ 897,903 

(1)Includes our sale, through a series of transactions, of ownership interests in data center shells through newly-formed unconsolidated real estate joint ventures in 2020 and 2019, as described in Note 4 to our consolidated financial statements.