BLM maintains an inventory of known abandoned mine lands on public lands. Most of the sites are abandoned hardrock mines. As of January 10, 2013, the inventory contained nearly 39,000 sites and 76,600 features. Approximately 23% of the sites have either been remediated, have reclamation actions planned or underway, or do not require further action.  The remaining 77% require further investigation and/or remediation.  

Abandoned Mine Lands Site Status (01/10/2013)
Geographic State	Action Completed (A)	Final Closeout(B)	In Progress (C)	Maintenance and  Monitoring(D)	Needs Analysis (E)	No Action (F)	Planned (G)	Total:	Remaining Sites (C+D+E+G)
Alaska	21	12	15	1	70	76	17	212	103
Arizona	118	175	30	100	2,675	623	276	3,997	3,081
California	133	1	47	10	1,223	114	314	1,842	1,594
Colorado	747	2	52	2	2,160	243	95	3,301	2,309
Idaho	246		40	152	240	292	163	1,133	595
Montana	381		118	1	442	224	40	1,206	601
Nevada	647	218	65		14,683	45	712	16,370	15,460
New Mexico	554		26		3,485	27	391	4,483	3,902
Oregon	33		8	48	640	31	8	768	704
Utah	2,426		620	4	188	1,278	12	4,528	824
Washington	13		16	0	63	2	8	102	87
Wyoming	58	30	3	18	859	40	32	1,040	912
Total:	5,377	438	1,040	336	26,728	2,995	2,068	38,982	30,172

Source: BLM's AML inventory database.

*This data should be considered soft because the BLM is currently reviewing and updating its data. In addition, the majority of sites were reported during the initial inventory efforts from various sources, but have not been assessed on the ground by the BLM.