Sec. 621. Entry to lands reserved for power development. (a) Conditions of entry. (b) Placer claims; notice; hearing; order; rules and regulations. (c) Validity of withdrawals unaffected. 622. Liability for damage, destruction, or loss of claim. 623. Recording and reporting of unpatented claims; time. 624. Protection of existing valid claims. 625. Prohibition of unspecified use.